Text and Data Mining valid from 2020-01-09
Received: 31 October 2019
Accepted: 27 December 2019
First Online: 9 January 2020
Compliance with Ethical Standards
: The authors declare no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This study was approved by the research ethics committee.
: Not required for this type of study.