Sheikh, B N
Bechtel-Walz, W
Lucci, J
Karpiuk, O
Hild, I
Hartleben, B
Vornweg, J
Helmstädter, M
Sahyoun, A H
Bhardwaj, V
Stehle, T
Diehl, S
Kretz, O
Voss, A K
Thomas, T
Manke, T
Huber, T B
Akhtar, A
Article History
Received: 29 November 2014
Revised: 9 July 2015
Accepted: 4 August 2015
First Online: 21 September 2015
Competing interests
: The authors declare no conflict of interest.