1. UNIVERSITY OF CRETE, HERACLION, GREECE
2. L.T. MALA NIT NATIONAL ACADEMY OF MEDICAL SCIENCES OF UKRAINE, KHARKIV, UKRAINE
3. IVANO-FRANKIVSK NATIONAL MEDICAL UNIVERSITY, IVANO-FRANKIVSK, UKRAINE
4. UNIVERSITY WITTEN-HERDECKE, WUPPERTAL, GERMANY
5. UNIVERSITY OF IOANNINA, IOANNINA, GREECE