1. NIS a.d. Novi Sad, 21102 Novi Sad, Serbia
2. Faculty of Technical Science, University of Novi Sad, 21000 Novi Sad, Serbia
3. Faculty of Science, University of Kragujevac, 34000 Kragujevac, Serbia
4. College of Applied Studies of Organization “EDUKA”, 11000 Belgrade, Serbia
5. Faculty of Economics, Technical University of Kosice, 04200 Kosice, Slovakia