Osterholz, Helena
Singer, Gabriel
Wemheuer, Bernd http://orcid.org/0000-0002-1712-7871
Daniel, Rolf
Simon, Meinhard
Niggemann, Jutta http://orcid.org/0000-0003-1237-9233
Dittmar, Thorsten
Article History
Received: 4 June 2015
Revised: 26 October 2015
Accepted: 6 November 2015
First Online: 22 January 2016
Competing interests
: The authors declare no conflict of interest.