1. Department of Pharmacology, Toxicology and Pharmacotherapy, Faculty of Pharmacy, Medical University of Varna “Prof. Dr. Paraskev Stoyanov”, Varna, Bulgaria
2. Department of Biology, Faculty of Pharmacy, Medical University of Varna “Prof. Dr. Paraskev Stoyanov”, Varna, Bulgaria
3. Department of General and Clinical Pathology, Forensic Medicine and Deontology, Division of General and Clinical Pathology, Faculty of Medicine, Medical University of Varna “Prof. Dr. Paraskev Stoyanov”, Varna, Bulgaria