Fassbender, Philipp http://orcid.org/0000-0002-7286-8699
Bürgener, Silja
Haddad, Ali
Silvanus, Marie-Therese
Peters, Jürgen
Article History
Received: 12 October 2017
Accepted: 19 January 2018
First Online: 27 January 2018
Ethics approval and consent to participate
: The study was approved by the ethic committee of the university of Essen-Duisburg (Reference number 06–3228) and written consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.
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