Text and Data Mining valid from 2019-02-06
Received: 15 December 2018
Accepted: 18 December 2018
First Online: 6 February 2019
Compliance with Ethical Standards
: The authors declare that they have no conflicts of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
: For this type of study, informed consent is not required.