Text and Data Mining valid from 2018-11-28
Received: 4 October 2018
Accepted: 25 November 2018
First Online: 28 November 2018
Compliance with ethical standards
: The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.
: All procedures performed in this study, involving human participants, were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.