1. Clinic of Ophthalmology, Faculty of Medicine, University of Nis, Blvd. Dr Zorana Djindjica 81, 18000 Nis, Serbia
2. Department of Anatomy, Faculty of Medicine, University of Nis, 18000 Nis, Serbia
3. Clinic of Nephrology, Faculty of Medicine, University of Nis, 18000 Nis, Serbia
4. Department of Statistics, State University of Novi Pazar, 36300 Novi Pazar, Serbia
5. Health Center Nis, 18000 Nis, Serbia
6. Clinic of Neurosurgery, University Clinical Center of Nis, 18000 Nis, Serbia