1. Faculty of Informatics and Computing, Singidunum University, 11010 Belgrade, Serbia
2. Teacher Education Faculty, University of Pristina in Kosovska Mitrovica, 38220 Kosovska Mitrovica, Serbia
3. Department of Applied Informatics, Vytautas Magnus University, 44404 Kaunas, Lithuania
4. School of Electrical Engineering, University of Belgrade, 11000 Belgrade, Serbia