KluszczyĆski, Marek
Pilis, Anna
Czaprowski, Dariusz
Article History
Received: 7 October 2021
Accepted: 25 November 2021
First Online: 3 January 2022
Declarations
:
: This study was approved by the Jan Dlugosz University in Czestochowa Ethical Committee KE-U/7/2021 and conducted under the Declaration of Helsinki. All the parents of the subjects were kept informed of the purpose and process of examination and subsequently gave their written consent before the study.
: All the parents of the subjects were kept informed of the purpose and process of examination and subsequently gave their written consent before the study.
: The authors declare no conflict of interest.