Text and Data Mining valid from 2018-07-16
Received: 20 November 2017
Accepted: 9 July 2018
First Online: 16 July 2018
Ethics approval and consent to participate
: The study has ethical approval from the Norwegian Social Science Data Services (NSD) (Ref. 48,267, 06 May 2016). All participants signed a consent form, which was also approved by the Norwegian Social Science Data Services.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.