Kaartvedt, Stein
Ugland, Karl I.
Klevjer, Thor A.
Røstad, Anders
Titelman, Josefin
Solberg, Ingrid
Article History
Received: 2 February 2015
Accepted: 18 May 2015
First Online: 11 June 2015
Competing interests
: The authors declare no competing financial interests.