Text and Data Mining valid from 2018-12-07
Received: 3 November 2018
Accepted: 3 December 2018
First Online: 7 December 2018
Compliance with ethical standards
: The authors declare that they 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 is not required for this type of study.