1. Laboratory of Experimental Surgery and Surgical Research; School of Medicine; Democritus University of Thrace; Alexandroupolis Greece
2. Laboratory of Histology and Embryology; School of Medicine; Democritus University of Thrace; Alexandroupolis Greece
3. First Surgical Clinic; School of Medicine; University of Belgrade; Belgrade Serbia
4. Clinic of Surgery; School of Medicine; University of Thessaly; University Hospital of Larissa; Larissa Greece