1. Department of Administration and Public Management, Faculty of Administration and Public Management, Bucharest University of Economic Studies, Piața Romană, 010371 Bucharest, Romania
2. Department of Transport Technology and Logistics, Faculty of Operation and Economics of Transport and Communications, University of Zilina, 01026 Zilina, Slovakia
3. Department of Economics, Faculty of Operation and Economics of Transport and Communications, University of Zilina, 01026 Zilina, Slovakia