Woźniakowski, Grzegorz
Frączyk, Magdalena
Kowalczyk, Andrzej
Pomorska-Mól, Małgorzata
Niemczuk, Krzysztof
Pejsak, Zygmunt
Article History
Received: 30 June 2016
Accepted: 3 January 2017
First Online: 15 February 2017
Competing interests
: The authors declare no competing financial interests.