1. Department of Organization and Management in Health Care, Poznan University of Medical Sciences, Poznań, Poland.
2. Department of Psychology, West Kazakhstan Marat Ospanov Medical University, Aktobe, Kazakhstan.
3. Department of Normal Physiology, West Kazakhstan Marat Ospanov Medical University, Aktobe, Kazakhstan.
4. Department of Social Sciences and Humanities, Poznan University of Medical Sciences, Poznań, Poland.