1. University Hospital of Obstetrics and Gynecology "Maichin Dom", Sofia, Bulgaria
2. Department of Obstetrics and Gynecology, Faculty of Medicine, Medical University, Sofia, Bulgaria
3. Health Care Department, Faculty of Public Health “Prof. Tzekomir Vodenicharov, МD, DSc”, Medical University of Sofia, Sofia, Bulgaria
4. Department of Health Policy and Management, Faculty of Public Health” Prof. Tzekomir Vodenicharov, МD, DSc”, Medical University of Sofia, Sofia, Bulgaria