Izdebski, Zbigniew
Wąż, Krzysztof
Kowalewska, Anna http://orcid.org/0000-0002-8476-9911
Mazur, Joanna
Article History
Received: 11 May 2020
Revised: 15 July 2020
Accepted: 25 August 2020
First Online: 2 September 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. Questionnaire and study procedures were approved by the board of participating school and parents’ council if the board required it. Students were informed about the objectives of the study and consented to participate. The survey was anonymous and students deposited filled questionnaires in the sealed envelopes.