Mayer, Arnulf
Zahnreich, Sebastian
Brieger, Jürgen
Vaupel, Peter
Schmidberger, Heinz
Article History
Received: 6 June 2016
Revised: 15 August 2016
Accepted: 21 September 2016
First Online: 1 November 2016
Competing interests
: The authors declare no conflict of interest.