Loeffler, M
Kreuz, M
Haake, A
Hasenclever, D
Trautmann, H
Arnold, C
Winter, K
Koch, K
Klapper, W
Scholtysik, R
Rosolowski, M
Hoffmann, S
Ammerpohl, O
Szczepanowski, M
Herrmann, D
Küppers, R
Pott, C
Siebert, R
,
Article History
Received: 21 February 2014
Revised: 8 May 2014
Accepted: 25 June 2014
First Online: 16 July 2014
Competing interests
: The authors declare no conflict of interest.