Text and Data Mining valid from 2018-10-27
Received: 15 May 2018
Accepted: 19 October 2018
First Online: 27 October 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.
: For this type of study formal consent is not required.