1. Faculty of Management and Economics, Tomas Bata University in Zlín, Mostní 5139, 760 00 Zlín, Czech Republic
2. Faculty of Operation and Economics of Transport and Communications, University of Zilina, Univezitna 1, 010 26 Zilina, Slovakia
3. Faculty of Management, University of Prešov in Prešov, Konštantínova 16, 080 01 Prešov, Slovakia
4. Faculty of Management, University of Prešov in Prešov, Konštantínova 16, 080 01 Prešov, Slovakia; Faculty of Mining, Ecology, Process Control and Geotechnologies, Technical University of Košice, Letná 9, 042 00 Košice, Slovakia