1. Niška Banja Institute for Treatment and Rehabilitation, Niš, Serbia
2. Aleksinac General Hospital, Aleksinac, Serbia
3. Doljevac Health Center, Doljevac, Serbia
4. Niška Banja Institute for Treatment and Rehabilitation, Niš, Serbia + University of Niš; Faculty of Medicine, Niš, Serbia
5. Cardio Point, Clinic for Cardiovascular Diseases Niš, Serbia