1. Niš University Clinical Centre, Clinic of Anesthesiology, Niš, Serbia + Niš University Clinical Centre, Clinic of Gynaecology and Obstetrics, Niš, Serbia
2. Niš University Clinical Centre, Clinic of Anesthesiology, Niš, Serbia + University of Niš, Faculty of Medicine, Niš, Serbia
3. Niš University Clinical Centre, Clinic of Gynaecology and Obstetrics, Niš, Serbia + University of Niš, Faculty of Medicine, Niš, Serbia