Rettig, I
Koeneke, E
Trippel, F
Mueller, W C
Burhenne, J
Kopp-Schneider, A
Fabian, J
Schober, A
Fernekorn, U
von Deimling, A
Deubzer, H E
Milde, T
Witt, O
Oehme, I
Article History
Received: 29 October 2014
Revised: 29 December 2014
Accepted: 12 January 2015
First Online: 19 February 2015
Competing interests
: The authors declare no conflict of interest.