Schleich, K
Buchbinder, J H
Pietkiewicz, S
Kähne, T
Warnken, U
Öztürk, S
Schnölzer, M
Naumann, M
Krammer, P H
Lavrik, I N
Article History
Received: 25 April 2014
Revised: 30 July 2015
Accepted: 3 August 2015
First Online: 23 October 2015
Competing interests
: The authors declare no conflict of interest.