1. Department of Pathology, University Hospital Prof St. Kirkovich, Stara Zagora, Bulgaria
2. Department of General and Clinical Pathology, Medical Faculty, Trakia University, Stara Zagora, Bulgaria
3. Department of Anatomy, Histology and Embriology, Pathology, Latin language, Forensic Medicine and Deontology, Faculty of Medicine, University Prof. Dr. Assen Zlatarov, Burgas, Bulgaria
4. Department of Medical Chemistry and Biochemistry, Medical Faculty, Trakia University, Stara Zagora
5. Department of Surgery, Medical Faculty, Trakia University, Stara Zagora, Bulgaria
6. Complex Oncology Centre, Stara Zagora, Bulgaria
7. Department of Medical Biochemistry, Faculty of Pharmacy, Medical University of Plovdiv, Plovdiv, Bulgaria