Kantorová, E
Marcinek, J
Zeleňák, K
Kantor, K
Michalik, J
Sivák, Š
Kurča, E
Plank, L
Article History
Received: 7 May 2014
Revised: 11 February 2015
Accepted: 24 February 2015
First Online: 30 June 2015
Competing interests
: The authors declare no conflict of interest.