Text and Data Mining valid from 2019-08-23
Received: 9 April 2019
Accepted: 4 August 2019
First Online: 23 August 2019
Compliance with ethical standards
: All authors declare that they have no conflict of interest.
: Ethical approval is not required for this project as it did not include the publication or distribution of any protected information.
: 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.