Heggeset, Tonje M. B.
Ertesvåg, Helga
Liu, Bin
Ellingsen, Trond E.
Vadstein, Olav
Aasen, Inga Marie
Article History
Received: 26 August 2019
Accepted: 4 December 2019
First Online: 19 December 2019
Competing interests
: The authors declare no competing interests.