Text and Data Mining valid from 2019-06-08
Received: 11 April 2019
Accepted: 2 June 2019
First Online: 8 June 2019
Compliance with ethical standards
: KS and DS declare no conflict of interest related to this paper.
: 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.