1. Faculty of Economy, J. Selye University, Bratislavská cesta 3322, 945 01 Komárno, Slovakia
2. John von Neumann Faculty of Informatics, Obuda University, Becsi ut 96/b, 1034 Budapest, Hungary
3. Doctoral School of Applied Informatics and Applied Mathematics, Obuda University, Becsi ut 96/b, 1034 Budapest, Hungary