Article History
Received: 12 June 2020
Accepted: 8 January 2021
First Online: 18 January 2021
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All procedures performed in the study were in accordance with the ethical standards of the National Lithuanian Ethics Board committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: The parents of all participants have given their written informed consent.