Hulliger, Beat
Sterchi, Martin
Article History
Received: 8 June 2018
Accepted: 29 October 2018
First Online: 13 November 2018
Competing interests
: The authors declare that they have no competing interests. All the funding institutions support the publication of this article. This study was conducted according to scientific criteria and none of the funding institutions had an influence on the outcome of the study.
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