Brustugun, Odd Terje
Article History
Received: 31 March 2019
Revised: 12 April 2019
Accepted: 12 April 2019
First Online: 22 May 2019
Ethics approval and consent to participate
: Not applicable.
: Not applicable.
: The author declares no competing interests.
: The author declares that there has been no funding to declare.
: This work is published under the standard license to publish agreement. After 12 months the work will become freely available and the license terms will switch to a Creative Commons Attribution 4.0 International (CC BY 4.0).
Free to read: This content has been made available to all.