1. Department of General Surgery, Stara Zagora University Hospital, Bulgaria
2. Department of Orthopaedics, Stara Zagora University Hospital, Bulgaria
3. Department of Pediatric Surgery, Medical University, Plovdiv, Bulgaria
4. Department of Orthopaedics and Traumatology, Medical University, Plovdiv, Bulgaria
5. Departmet of Pathology, Medical University, Plovdiv, Bulgaria