Text and Data Mining valid from 2018-05-18
Received: 6 December 2017
Accepted: 2 May 2018
First Online: 18 May 2018
Compliance with ethical standards
: The author declares that she has 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.