Almåsbak, H
Walseng, E
Kristian, A
Myhre, M R
Suso, E M
Munthe, L A
Andersen, J T
Wang, M Y
Kvalheim, G
Gaudernack, G
Kyte, J A
Article History
Received: 28 June 2014
Revised: 3 November 2014
Accepted: 6 January 2015
First Online: 5 February 2015
Competing interests
: The authors declare no conflict of interest.