1. Faculty of Medicine, University of Belgrade, Belgrade, Serbia
2. Clinic for Neurosurgery, Clinical Center of Serbia, Belgrade, Serbia
3. Section for Neurosurgery, Department of Surgery, Ćuprija General Hospital, Ćuprija, Serbia
4. Faculty of Medicine of the Military Medical Academy, University of Defense, Belgrade, Serbia
5. Clinic for Neurosurgery, Military Medical Academy, Belgrade, Serbia
6. Department of Surgery, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
7. “Sport Academy Belgrade”, College of Higher Vocational Studies, Belgrade, Serbia