1. Department of Propedeutics of Surgical Diseases, Section of General Surgery, Medical University – Plovdiv, Bulgaria
2. Clinic of General Surgery, University Hospital “St. George – Plovdiv, Bulgaria
3. Department of Medical Oncology, MHAT “Central Onco Hospital” – Plovdiv, Bulgaria
4. Department of General and Clinical Pathology and Forensic Medicine, Medical University – Plovdiv, Bulgaria