Ulstad, Svein Olav http://orcid.org/0000-0003-3172-4370
Halvari, Hallgeir
Sørebø, Øystein
Deci, Edward L.
Article History
First Online: 6 April 2018
Compliance with ethical standards
:
: All procedures performed in the study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The project is approved by the Norwegian social science data services (NSD). The parents were informed about the project and had to agree to the participation of their children in the project.