Text and Data Mining valid from 2019-04-08
Received: 16 January 2019
Accepted: 22 March 2019
First Online: 8 April 2019
Compliance with ethical standards
: We declare that we have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
: Informed consent was obtained from all individual participants included in the study.