Knobel, Alexander http://orcid.org/0000-0002-1964-4610
Overheu, Daniel
Gruessing, Matthias
Juergensen, Ingke
Struewer, Johannes
Article History
Received: 4 August 2017
Accepted: 25 May 2018
First Online: 7 June 2018
Ethics approval and consent to participate
: Our retrospective study used a strictly anonymous design therefore informed consent was not necessary. The study was approved by the ethics committee of the Carl von Ossietzky Universität Oldenburg (approval number 089/2016).
: The authors declare that they have no competing interests.
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