Received: 5 July 2018
Accepted: 31 January 2019
First Online: 19 February 2019
Ethics approval and consent to participate
: The study protocol was approved by the institute’s internal scientific committee. Participants were informed twice via e-mail and via the questionnaire about the goal of the study, the extent of time and effort required, the anonymity of results and the voluntary nature of participation.
: Not applicable.
: The authors declare that they have no competing interests.
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