Daldorff, Stine
Mathiesen, Randi Margit Ruud
Yri, Olav Erich
Ødegård, Hilde Presterud
Geisler, Jürgen
Article History
Received: 10 August 2016
Revised: 28 October 2016
Accepted: 8 November 2016
First Online: 6 December 2016
Competing interests
: The authors declare no conflict of interest.