Max, Nicole
Harbaum, Lars
Pollheimer, Marion J
Lindtner, Richard A
Kornprat, Peter
Langner, Cord
Article History
Received: 20 October 2015
Revised: 29 November 2015
Accepted: 7 December 2015
First Online: 14 January 2016
Competing interests
: The authors declare no conflict of interest.