Funding for this research was provided by:
Text and Data Mining valid from 2020-01-10
Received: 29 March 2019
Accepted: 19 December 2019
First Online: 10 January 2020
Compliance with ethical standards
: On behalf of all authors, the corresponding author states that there is no conflict of interest. Funders did not have any influence on the design of the study, or the interpretation of the results.
: The authors declare this study to be in compliance with ethical standards.