Petersen, D L
Krejsgaard, T
Berthelsen, J
Fredholm, S
Willerslev-Olsen, A
Sibbesen, N A
Bonefeld, C M
Andersen, M H
Francavilla, C
Olsen, J V
Hu, T
Zhang, M
Wasik, M A
Geisler, C
Woetmann, A
Odum, N
Article History
First Online: 12 June 2014
Competing interests
: The authors declare no conflict of interest.