Toft, N
Birgens, H
Abrahamsson, J
Griškevičius, L
Hallböök, H
Heyman, M
Klausen, T W
Jónsson, ÓG
Palk, K
Pruunsild, K
Quist-Paulsen, P
Vaitkeviciene, G
Vettenranta, K
Åsberg, A
Frandsen, T L
Marquart, H V
Madsen, H O
Norén-Nyström, U
Schmiegelow, K
Article History
Received: 2 May 2017
Revised: 6 August 2017
Accepted: 9 August 2017
First Online: 18 August 2017
Competing interests
: The authors declare no conflict of interest.