1. University Clinical Center of the Republic of Srpska, Clinic for General and Abdominal Surgery, Banjaluka, Bosnia and Herzegovina
2. University of Kragujevac, Faculty of Medical Sciences, Department of Anatomy and Forensic Medicine, Kragujevac, Serbia + University of Defence, Faculty of Medicine of the Military Medical Academy, Belgrade, Serbia
3. Clinical Center Kragujevac, General and Thoracic Surgery Department, Kragujevac, Serbia + University of Kragujevac, Faculty of Medical Sciences, Department of Surgery, Kragujevac, Serbia
4. University of Kragujevac, Faculty of Medical Sciences, Department of Pediatrics, Kragujevac, Serbia
5. University of Kragujevac, Faculty of Medical Sciences, Department of Internal Medicine, Kragujevac, Serbia