1. Clinical Hospital Center, 38220 Kosovska Mitrovica, Serbia
2. Faculty of Medicine, University of Pristina, 38220 Kosovska Mitrovica, Serbia
3. Institute for Mother and Child Health Care “Dr Vukan Čupić”, 11070 Belgrade, Serbia
4. Faculty of Medicine, University of Belgrade, 11000 Begrade, Serbia
5. Clinic for Pediatric Surgery, Orthopedics and Traumatology, University Clinical Center, 18000 Nis, Serbia
6. Faculty of Medicine, University of Nis, 18000 Niš, Serbia