1. Department of Medical Chemistry and Biochemistry, Medical Faculty, Trakia University, 6000 Stara Zagora, Bulgaria
2. Department of Surgery, Neurosurgery, Urology and Anaesthesiology, Medical Faculty, Trakia University, 6000 Stara Zagora, Bulgaria
3. Department of General and Clinical Pathology, Forensic Medicine, Deontology and Dermatovenerology, Medical Faculty, Trakia University, 6000 Stara Zagora, Bulgaria