Kocová, Valéria
Straková, Nikola
Kolarčik, Vladislav
Rákai, Albert
Mártonfi, Pavol
Funding for this research was provided by:
VEGA Grant Agency (Slovakia) (1/0163/15)
VVGS grant (P. J. Šafárik University in Košice, Slovakia) (VVGS-PF-2015-493)