Authors
Pavol Kita
Faculty of Arts, Comenius University, Bratislava, Slovakia
Grzegorz Maciejewski
grzegorz.maciejewski@ue.katowice.pl
Faculty of Economics, University of Economics in Katowice, Katowice, Poland
Marta Žambochová
Department of Mathematical and Informatic, Purkyně University, Ústí nad Labem, Czech Republic
František Križan
Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia