1. Zemun Clinical Center, Department of Gynecology and Obstetrics, Belgrade, Serbia
2. University of Belgrade, Faculty of Medicine, Belgrade, Serbia + Narodni Front Clinic of Gynecology and Obstetrics, Belgrade, Serbia
3. University of Kragujevac, Faculty of Medical Sciences, Clinic of Gynecology and Obstetrics, Kragujevac, Serbia
4. University of Kragujevac, Faculty of Medical Sciences, Clinic of Gynecology and Obstetrics, Kargujevac, Serbia
5. Narodni Front Clinic of Gynecology and Obstetrics, Belgrade, Serbia
6. ICT College of Applied Studies, Belgrade, Serbia