ABSTRACT | PDF

ORIGINAL RESEARCH PAPER

Exploring the role of compassion satisfaction and compassion fatigue in predicting burnout among police officers

Konstantinos Papazoglou1, Mari Koskelainen2, Natalie Stuewe1

1University of Toronto, Mississauga Campus, Mississauga, Ontario, Canada, 2Police University College of Finland, Tampere, Finland

Abstract

Objective: Prior research on police practices has highlighted the plethora of operational and organisational stressors that police officers face throughout their careers. Work-related demands, acute stress, and lack of organisational support and resources may lead officers to experience burnout, which is characterised by emotional exhaustion, lack of professional efficacy, depersonalisation, and cynicism. Prior research studies have consistently demonstrated burnout’s significant impact on police officers’ mental and physical health, and they have also shown that traumatisation (specifically compassion fatigue) appears to be associated with burnout among police officers. The present study aims to examine the prevalence of burnout among police officers and to identify the association of burnout with compassion fatigue, compassion satisfaction, and years of experience. Setting: Data collection occurred in cooperation with the National Police of Finland, and all officers who may potentially experience work-related trauma were invited to participate. Participants: Study participants were police officers from the National Police of Finland (n=1,173). Main outcome measures: Compassion Satisfaction and Fatigue Test and demographics questions. Results: Data analyses indicated that most study participants (78.03% or n=945) reported low levels of burnout. Moreover, burnout was found to be significantly positively correlated with compassion fatigue (r=0.76; p<0.01) and years of experience (r=0.10; p<0.01), but significantly negatively correlated with compassion satisfaction (r=-0. 49; p<0.01). Furthermore, hierarchical linear regression indicated that years of experience, compassion satisfaction, and compassion fatigue were significant predictors of burnout. Conclusions: Authors discuss various interpretations, implications, and limitations of the current study’s findings, as well as providing recommendations for future research.

Keywords: Stress. Trauma. Experience.

Correspondence: Dr. Konstantinos Papazoglou, Ph.D. in Psychology (Clinical-Forensic area), Department of Psychology, University of Toronto, Mississauga Campus, DeerField Hall, Room #4044, Mississauga, Ontario, Canada, L5L 1C6. kons.papazoglou@mail.utoronto.ca

Received: 13 July 2017

Revised: 25 July 2017

Accepted: 23 August 2017

Epub: 1 November 2017

DOI: 10.5958/2394-2061.2018.00020.4

INTRODUCTION

Burnout in police work

Although police officers experience numerous work-related stressors, scholars have identified three main categories into which these stressors fall: personal, organisational, and operational.[1-4] Personal stressors may refer to sources of stress in officers’ personal lives or particular personality traits (e.g. anxiety, sensitivity). On the other hand, operational stressors refer to stress that results from interactions with victims and perpetrators of crimes. Finally, organisational stressors encompass a variety of non-frontline job-related aspects, such as interactions with authoritarian supervisors, a lack of understanding from peers, heavy paperwork, bureaucratic processes, and limited opportunities for career advancement. Researchers have argued that, if police officers are not provided with effective stress-management skills or adequate access to organisational support and resources, continued exposure to work-related demands will cause them to become prone to experiencing burnout.[3,5,6] Burnout refers to emotional exhaustion, lack of professional efficacy, depersonalisation, and cynicism that an officer may experience.[7-9] Furthermore, officers suffering from burnout experience decreased motivation, low levels of interest in advancing the organisation’s mission, and a lack of energy and attention.[3,10] As a result, burnout precludes officers from accomplishing work-related goals, implementing solutions to work-related issues, and generally performing their duties effectively.[11,12]

Burnout and health

Past research has demonstrated the inverse relationship between burnout and health among healthcare professionals.[13-15] In their systematic review of burnout’s impact on health outcomes among nurses,[16] researchers found that nurses who experienced burnout also suffered from headaches, mental distress, anxiety, depression, psychosomatic complaints, and overall poor health. These findings were corroborated by previous study[15] of healthcare workers in Sweden (n=3,719), which found that participants with high levels of burnout reported significantly higher levels of depression, anxiety, sleep disturbance, memory impairment, and psychosomatic issues than those with lower levels of burnout. Furthermore, in their work with Indian software developers (n=372), researchers[17] found that employees with higher levels of burnout reported more mental and physical health issues than those who reported lower burnout levels. Interestingly, respondents with higher burnout rates were more likely to experience severe mental health issues (i.e. anxiety, depression, social dysfunction, loss of confidence) than they were to report problems with their physical health (e.g. loss of appetite, sleeplessness, racing heart rate) or behaviour (e.g. alcohol consumption, smoking). Similarly, a longitudinal study recruited social workers (n=406) in California[18] showed that participants who reported high levels of burnout also experienced physical health deterioration (i.e. gastrointestinal problems, headaches, respiratory infections, overall physical health) over the three-year data collection period, which further demonstrates the negative relationship between burnout and physical wellbeing that occurs over time.

Research findings regarding burnout’s impact on the health of police officers are consistent with the above-discussed studies focusing on healthcare professionals.[19] In their study of 223 Norwegian police officers, researchers[20] found that burnout mediated the relationship between work-related demands and health-related problems (e.g. psychosomatic complaints, poor appetite, and headaches). Likewise, similar results were reported by researchers studying police officers in Poland.[21] Nevertheless, the direction of the relationship between burnout and health among police officers remains an open question. While some police researchers have contended that poor health may contribute to burnout, others suggested that burnout may in fact lead to poor health.[22] The impact of burnout on caregiving professionals’ mental and physical health can be incapacitating; as a result, they may quit their jobs prematurely or decide to move to a different position that offers them more resources and work-related social support.[13,23]

Police compassion fatigue and compassion satisfaction

Compassion fatigue was first conceptualised by Charles Figley, a Vietnam veteran and clinical research professor. In his clinical work with veterans, Figley[24] noticed that, over time, he began to feel emotionally overwhelmed. To define this condition, Figley[24] coined the term “compassion fatigue,” which he described as the “cost of caring for those who suffer” (p.9). Empirical research has shown that compassion fatigue may have a detrimental effect on frontline professionals’ (e.g. clinicians, medical doctors, nurses) mental and physical health as well as their occupational performance.[25,26] However, not all caregiving professionals experience compassion fatigue, and many report experiencing its opposite: compassion satisfaction. Stamm[27] introduced this term to describe the sense of motivation, achievement, and satisfaction that caregiving professionals feel as a result of being able to help those who are suffering. Violanti and Gehrke[28] were the first to address the issue of compassion fatigue in a law enforcement context, which they did in a pioneering theoretical article that was published in the International Journal of Emergency Mental Health. Afterwards, other researchers studied compassion fatigue by recruiting small samples of police officers[29] or including police officers in a broader sample of caregiving professionals.[30] Recognising the need for research exclusively focusing on police officers, the first author published an article that aimed to raise awareness about police compassion fatigue, and to highlight the necessity for more empirical research in this previously under-explored area.[31]

Compassion fatigue versus burnout

Compassion fatigue and burnout are commonly viewed as being almost identical conditions due to sharing many of the same symptoms, such as: emotional exhaustion, aloofness, depersonalisation, distress, somatic complaints, alcohol and drug abuse, and life disruption.[8,11,26] The impact of both burnout and compassion fatigue on frontline professionals’ health and wellbeing tends to accumulate over their years of service, especially if their effects remain unaddressed.[20,32] Both conditions can negatively affect caregiving professionals’ decision-making at work, their job performance, and their level of job satisfaction,[5] and they can also increase the likelihood that individuals will quit their jobs, be absent more frequently, and experience a loss of work motivation.[5] Although many researchers have categorised burnout and compassion fatigue as separate, yet overlapping conditions, there is compelling evidence to suggest that they are distinctly independent from one another.[8-10] In their research on trauma specialists,[7] noted that burnout is distinct from compassion fatigue in the sense that the symptoms of trauma exposure are not present in burnout. Specifically, burnout is defined by the experience of exhaustion, cynicism, and lack of professional efficacy as a result of high job demands (e.g. heavy workload, shift work), lack of resources at work (e.g. necessary equipment is not available), lack of social support from peers and supervisors, and excessive work-related stress.[3,10,20] On the other hand, Figley[24,26] emphasised that caregiving professionals may experience compassion fatigue due to a combination of prolonged exposure to traumatised victims and an inability to emotionally disengage themselves from the victims’ traumatic experiences (e.g. identification with the victim). It should be noted that compassion fatigue may occur if caregiving professionals ignore or deny the initial compassion fatigue cues (or residuals) and do not seek help to address those issues before they become debilitating. Prominent trauma scholar, Yael Danieli[33] observed that, in some occasions, caregiving professionals who suffer from compassion fatigue may even dissociate during their work with traumatised individuals, which puts emphasis on the fact that compassion fatigue is emanated from caregiving professionals’ work in a trauma-related context. Therefore, there is considerable evidence to suggest that compassion fatigue can be distinguished from burnout based on the experience of trauma exposure.

Aims and hypotheses

Aim 1. The present study aims to examine the prevalence rates of burnout among police officers.

Hypothesis 1. It is expected that officers will report elevated levels of burnout consistent with a chronic exposure to stress.

Aim 2. To explore the relationship of burnout with the following variables: compassion fatigue, compassion satisfaction, and years of experience.

Hypothesis 2. It is hypothesised that burnout will be negatively correlated with compassion satisfaction and positively correlated with compassion fatigue. In addition, authors contend that years of experience are associated with burnout on the grounds that officers experience multiple potentially traumatic incidents and a plethora of stressors over the course of their career.

Aim 3. To examine the role of certain variables (compassion fatigue, compassion satisfaction, years of police) in predicting burnout.

Hypothesis 3. It is expected that compassion fatigue, compassion satisfaction, and years of experience will be significant predictors of compassion fatigue.

METHODS

Participants

Study participants were police officers from the National Police of Finland (all White European) (n=1,173) and majority of them males (n=880). During data collection, all participants served in positions (e.g. operational offices, police dispatchers, crime investigators) that entail exposure to acute stress and potential trauma.

Procedures

Authors of current study collected data using an online internal police survey programme called “Webropol” which is supported and coordinated by the National Police of Finland. This is a common high security web network used within Finland to distribute surveys to everyone employed by the National Police of Finland. Survey study web links were provided to police officers within various police departments across Finland. In addition, the study weblink was sent to the National Bureau of Investigation, the Police University College, and the Security Intelligence Service. The weblink to the survey was administered to officers from across Finland and they were encouraged to participate in the study. Participation was completely voluntary and participants did not receive any compensation for completing the survey. After clicking the weblink, participants were asked to give their consent to participate in the study; after consent was provided, they then answered demographic questions on topics such as their length of service and current area of work. Following the demographic questions, they then completed the survey study questionnaire, which is described in the following section. Study participation occurred during work shift hours. It should be noted that before the initiation of the data collection, the proposed study was first approved by the University of Toronto Research Ethics Board as well as the National Research Board of the National Police of Finland.

Measures

Demographics. Demographics questions entailed the following components: age, years of service, and gender. In addition, demographics questions included questions regarding participants’ racial and ethnic background.

Compassion Satisfaction and Fatigue Test. The established “Compassion Satisfaction and Fatigue Self-Test for Helpers” (CSF) was used to assess the compassion fatigue and satisfaction variables.[27] The CSF test is a scale based on self-reporting and consists of three subscales with a total of 66 items. These items are presented on a Likert-type scale ranging from zero to five (zero=never to five=very often). The three subscales measure a person’s level of compassion fatigue, compassion satisfaction, and burnout, and the person’s score for each variable accordingly falls into one of the following categories: extremely low, low, moderate, high, and extremely high. The CSF shows good reliability with high Cronbach’s alpha reliability values on all three subscales; this is consistent with what was reported in previous research wherein compassion fatigue was 0.87, compassion satisfaction was 0.87, and burnout was 0.90.[25]

RESULTS

Aim 1. The present study aims to examine the prevalence rates of burnout among police officers: Most of study participants (78.03% or n=945) reported low levels of burnout in contrast to few participants (5.12% or n=62) who indicated moderate levels of burnout. Almost no participant (0.50% or n=six) reported high levels of burnout.

Aim 2. To explore the relationship of burnout with the following variables: compassion fatigue, compassion satisfaction, and years of experience: Pearson r correlational coefficient analysis showed that burnout was significantly positively correlated with years of service (r=0.10; p<0.001) (small correlation) and compassion fatigue (r=0.76; p<0.001) (large correlation). As well, burnout was found to be significantly negatively correlated with compassion satisfaction (r=-0.49; p<0.001) (moderate correlation).[34]

Aim 3. To examine the role of certain variables (compassion fatigue, compassion satisfaction, and years of police) in predicting burnout, multiple level regression analysis was performed (Table 1). The results showed that years of service (Model 1: B=0.109;p<0.001; Adjusted R2=0.013) and compassion satisfaction (Model 2: B=-0.489; p<0.001; Adjusted R2=0.251) were significant predictors of burnout. In addition, the greatest amount of variance in burnout was explained by compassion fatigue (Model 3: B=0.677; p<0.001; Adjusted R2=0.645).

DISCUSSION: IMPLICATIONS, LIMITATIONS, FUTURE RESEARCH

The present study’s findings indicated that most officers reported low levels of burnout, while a small percentage showed moderate levels. Significantly, the percentage of study participants who reported high levels of burnout was nearly imperceptible, which seems to contradict the prior research that suggested the prevalence of burnout in police work. One possible explanation for this finding may be that officers who experience high levels of burnout may decide to quit prematurely, move to positions with lower levels of workplace stress, or even receive leave of absence from the service. Indeed, previous research[20,35] has revealed that officers who suffer from burnout express greater intentions of quitting their positions or leaving their agency; therefore, it is also possible that the low number of participants reporting high levels of burnout is attributable to officers leaving their positions or the force when they experience intense burnout. Another potential explanation for the very low levels of reported burnout might be due to the fact that police officers are simply more resilient than the general population and are better predisposed to dealing with the plethora of acute stressors that they will encounter over the course of their career.[36,37]

Moreover, current study’s findings showed that burnout is significantly correlated with years of experience, compassion fatigue, and compassion satisfaction. Perhaps the most notable correlation in this respect was that burnout was weakly correlated to years of experience. There are two possible explanations for this result: first, as officers accumulate service time, their likelihood of quitting their position or leaving the agency increases; and, second, those officers who remain with the agency are able to do so by identifying and adopting effective ways of coping with burnout. Taking into consideration previous research in this area,[20,35] the authors assume a direct relationship between the amount of time an officer spends with an agency and the probability of them quitting or changing positions. Future research may shed light onto this issue and attempt to identify whether police officers become more resilient to burnout over their years of service, or if they simply quit their positions. For instance, future research may focus on officers who resign or decide to retire prematurely; thus, such a study will be able to identify an officer’s reasons for leaving the force, as well as their burnout levels at the time of their departure.

It was not surprising that burnout and compassion fatigue were significantly strongly correlated, as this relationship has been extensively documented in prior research on compassion fatigue among caregiving professionals.[24,26,31] As previously noted, burnout and compassion fatigue are two distinct conditions that share some common areas. The strong association between burnout and compassion fatigue among study participants indicates that those who are vulnerable to compassion fatigue are also susceptible to burnout, and vice versa. However, since the present study is correlational, the authors cannot infer causality in either direction. Future studies may consider adopting a quasi-experimental design in order to explore potential causal pathways between compassion fatigue and burnout. For instance, future research may compare and contrast the experiences of operational and administrative police officers or explore relationship between compassion fatigue and burnout longitudinally.

Furthermore, the current study’s findings showed moderately significant negative correlation between compassion satisfaction and burnout. This result is consistent with prior research in this area,[24,26,31] and it indicates that increases in compassion satisfaction lead to decreases in burnout, and vice versa. Therefore, future research may explore techniques for promoting compassion satisfaction, as this could be an effective way of reducing burnout levels. As with the relationship between compassion fatigue and burnout, the relationship between compassion satisfaction and burnout does not imply causality. As such, it would be highly useful for future research to examine potential causal connections between the above-mentioned variables.

Conclusion

Police work is highly demanding and entails a plethora of operational and organisational responsibilities. Burnout may have deleterious effects on officers’ mental and physical health as well as on their performance in the field. Nonetheless, it is critical that officers are cognizant of and take measures to prevent burnout and other health-related conditions that may jeopardise theirs or the public’s safety. Therefore, the authors strongly encourage further research that explores the ramifications of police burnout as well as strategies for helping to prevent it.

Previous literature has discussed various self-care techniques that front line professionals can use to help deal with compassion fatigue.[24,26] To this end, clinicians could teach police officers certain practical and easily applied self-care techniques that can be used to mitigate the effects burnout. Furthermore, these self-care techniques could be taught to police cadets and officers in the early stages of their careers as preventative strategies for dealing with the deleterious impact of burnout on their health and wellbeing. Clinicians may collaborate with police trainers, union representatives, and high-ranking police managers to incorporate self-care strategies in order to provide officers with support in managing burnout. Analogously, clinicians may play a vital role in helping officers improve their levels of compassion satisfaction. Clinicians may partner with high-ranking police managers to develop practices that identify and celebrate the successes of the department’s police officers during their last shift. For instance, briefing or de-briefing sessions are often mainly focused on the facts and any issues that may have emerged during the previous shift. However, clinicians could attend these meetings and work with officers and their supervisors to identify and focus on their successes, moments of gratitude, and pleasant social interactions that may have occurred during their shift. It appears that officers consider these types of acts to be routine aspects of their work (e.g. helping an elder cross the street, appreciating a civilian’s gesture to thank them) and, hence, they may not take the time to reflect upon and feel grateful for the services they provide for their communities.

REFERENCES

1.      Andersen JP, Papazoglou K, Koskelainen M, Nyman M, Gustafsberg H, Arnetz BB. Applying resilience promotion training among special forces police officers. Sage Open. 2015;5(2).

2.      Andersen JP, Papazoglou K, Koskelainen M, Nyman M. Knowledge and training regarding the link between trauma and health: a national survey of Finnish police officers. SAGE Open. 2015;5(2).

3.      Burke RJ, Mikkelsen A. Burnout among Norwegian police officers: potential antecedents and consequences. Int J Stress Manag. 2006;13:64-83.

4.      Papazoglou K. Managing effective transitions: presenting the different shades of police life and the pivotal role of mental health care providers in promoting officers’ wellbeing. Int J Med Health Sci. 2016;5:121-2.

5.      Salloum A, Kondrat DC, Johnco C, Olson KR. The role of self-care on compassion satisfaction, burnout and secondary trauma among child welfare workers. Child Youth Serv Rev. 2015;49:54-61.

6.      Vuorensyrjä M, Mälkiä M. Nonlinearity of the effects of police stressors on police officer burnout. Policing. 2011;34: 382-402.

7.      Craig CD, Sprang G. Compassion satisfaction, compassion fatigue, and burnout in a national sample of trauma treatment therapists. Anxiety Stress Coping. 2010;23:319-39.

8.      Hooper C, Craig J, Janvrin DR, Wetsel MA, Reimels E. Compassion satisfaction, burnout, and compassion fatigue among emergency nurses compared with nurses in other selected inpatient specialties. J Emerg Nurs. 2010;36:420-7.

9.      Wagaman MA, Geiger JM, Shockley C, Segal EA. The role of empathy in burnout, compassion satisfaction, and secondary traumatic stress among social workers. Soc Work. 2015;60:201-9.

10.  Conrad D, Kellar-Guenther Y. Compassion fatigue, burnout, and compassion satisfaction among Colorado child protection workers. Child Abuse Negl. 2006;30:1071-80.

11.  Jacobson JM. Risk of compassion fatigue and burnout and potential for compassion satisfaction among employee assistance professionals: protecting the workforce. Traumatology. 2012;18:64-72.

12.  Kula S. Occupational stress, supervisor support, job satisfaction, and work-related burnout: perceptions of Turkish National Police (TNP) members. Police Pract Res. 2017;18:146-59.

13.  Harwood L, Ridley J, Wilson B, Laschinger HK. Occupational burnout, retention and health outcomes in nephrology nurses. CANNT J. 2010;20:18-23.

14.  Iacovides A, Fountoulakis KN, Kaprinis S, Kaprinis G. The relationship between job stress, burnout and clinical depression. J Affect Disord. 2003;75:209-21.

15.  Peterson U, Demerouti E, Bergström G, Samuelsson M, Asberg M, Nygren A. Burnout and physical and mental health among Swedish healthcare workers. J Adv Nurs. 2008;62:84-95.

16.  Khamisa N, Peltzer K, Oldenburg B. Burnout in relation to specific contributing factors and health outcomes among nurses: a systematic review. Int J Environ Res Public Health. 2013;10:2214-40.

17.  Singh P, Suar D. Health consequences and buffers of job burnout among Indian software developers. Psychol Stud. 2013;58: 20-32.

18.  Kim H, Ji J, Kao D. Burnout and physical health among social workers: A three-year longitudinal study. Soc Work. 2011;56:258-68.

19.  Wu CH. Role conflicts, emotional exhaustion and health problems: a study of police officers in Taiwan. Stress Health 2009;25:259-65.

20.  Martinussen M, Richardsen AM, Burke RJ. Job demands, job resources, and burnout among police officers. J Crim Just. 2007;35:239-49.

21.  Baka L. The effects of job demands on mental and physical health in the group of police officers. Testing the mediating role of job burnout. Stud Psychol. 2015;57:285-99.

22.  Golembiewski RT, Lloyd M, Scherb K, Munzenrider RF. Burnout and mental health among police officers. J Public Adm Res Theory. 1992;2:424-39.

23.  Coates DD, Howe D. The design and development of staff wellbeing initiatives: staff stressors, burnout and emotional exhaustion at Children and Young People’s Mental Health in Australia. Adm Policy Ment Health. 2015;42:655-63.

24.  Figley CR. Compassion fatigue as secondary traumatic stress disorder: an overview. In: Figley CR, editor. Compassion fatigue: coping with secondary traumatic stress disorder in those who treat the traumatised. New York, NY: Brunner-Routledge; 1995:1-20.

25.  Bride BE, Radey M, Figley CR. Measuring compassion fatigue. Clin Soc Work J. 2007;35:155-63.

26.  Figley CR, editor. Treating compassion fatigue. New York, NY: Brunner-Routledge; 2002.

27.  Stamm BM. Measuring compassion satisfaction as well as fatigue: developmental history of the Compassion Satisfaction and Fatigue Test. In Figley CR, editor. Treating compassion fatigue. New York, NY: Brunner-Routledge, 2002:107-19.

28.  Violanti JM, Gehrke A. Police trauma encounters: precursors of compassion fatigue. Int J Emerg Ment Health. 2004;6:75-80.

29.  Lane EJ, Lating JM, Lowry JL, Martino TP. Differences in compassion fatigue, symptoms of posttraumatic stress disorder and relationship satisfaction, including sexual desire and functioning, between male and female detectives who investigate sexual offenses against children: a pilot study. Int J Emerg Ment Health. 2010;12:257-66.

30.  Tehrani N. Compassion fatigue: experiences in occupational health, human resources, counselling and police. Occup Med (Lond). 2010;60:133-8.

31.  Andersen JP, Papazoglou K. Compassion fatigue and compassion satisfaction among police officers: an understudied topic. Int J Emerg Ment Health. 2015;17:661-3.

32.  Perez LM, Jones J, Englert DR, Sachau D. Secondary traumatic stress and burnout among law enforcement investigators exposed to disturbing media images. J Police Crim Psychol. 2010;25:113-24.

33.  Danieli Y. Who takes care of the caretakers? The emotional consequences of working with children traumatized by war and communal violence. In: Apfel RJ, Simon B, editors. Minefields in their hearts: the mental health of children in war and communal violence. New Haven, CT: Yale University Press; 1996:189-205.

34.  Meyers LS, Gamst G, Guarino AJ. Applied multivariate research: design and interpretation. 2nd ed. Thousand Oaks, CA: Sage; 2013.

35.  Burke RJ. Stressful events, work-family conflict, coping, psychological burnout, and well-being among police officers. Psychol Rep. 1994;75:787-800.

36.  Galatzer-Levy IR, Madan A, Neylan TC, Henn-Haase C, Marmar CR. Peritraumatic and trait dissociation differentiate police officers with resilient versus symptomatic trajectories of posttraumatic stress symptoms. J Trauma Stress. 2011;24:557-65.

37.  Marmar CR, McCaslin SE, Metzler TJ, Best S, Weiss DS, Fagan J, et al. Predictors of posttraumatic stress in police and other first responders. Ann N Y Acad Sci. 2006;1071:1-18.

Papazoglou K, Koskelainen M, Stuewe N. Exploring the role of compassion satisfaction and compassion fatigue in predicting burnout among police officers. Open J Psychiatry Allied Sci. 2018;9:107-12. doi: 10.5958/2394-2061.2018.00020.4. Epub 2017 Nov 1.

Source of support: Nil. Declaration of interest: None.

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Nach oben