Text and Data Mining valid from 2019-02-18
Received: 6 December 2018
Accepted: 1 February 2019
First Online: 18 February 2019
Ethics approval and consent to participate
: Ethical approval for the study was granted by the Norwegian Centre for Research Data (NSD), under the Ministry of Education and Research. Reference number: 56423/3/OASR. Informed consent was obtained in written form, and all participants agreed to participate in the study.
: Not applicable.
: The authors declare that they have no competing interests.
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