Wibæk, R
Kæstel, P
Skov, S R
Christensen, D L
Girma, T
Wells, J C K
Friis, H
Andersen, G S
Article History
Received: 6 October 2014
Revised: 16 February 2015
Accepted: 26 February 2015
First Online: 1 April 2015
Competing interests
: The authors declare no conflict of interest.