Authors
Piotr Gorzelanczyk
piotr.gorzelanczyk@puss.pila.pl
Stanislaw Staszic University of Applied Sciences in Pila, Piła
Martin Jurkovič
martin.jurkovic@fpedas.uniza.sk
Faculty of Operation and Economics of Transport and Communications, University of Žilina, Žilina, Slovakia
Tomáš Kalina
Faculty of Operation and Economics of Transport and Communications, University of Žilina, Žilina, Slovakia