Irgens, I
Rekand, T http://orcid.org/0000-0002-2506-9501
Arora, M http://orcid.org/0000-0003-1024-3682
Liu, N
Marshall, R
Biering- Sørensen, F
Alexander, M
Article History
Received: 8 July 2017
Revised: 30 September 2017
Accepted: 9 October 2017
First Online: 7 March 2018
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.