Authors
Viera Vavrecková
University of Social and Administrative Affairs, V.Nezvala 1, 736 01,, Havírov, Czech Republic
Michaela Tichá
University of Social and Administrative Affairs, V.Nezvala 1, 736 01,, Havírov, Czech Republic
Zlata Ondrúšová
University of Social and Administrative Affairs, V.Nezvala 1, 736 01,, Havírov, Czech Republic