Text and Data Mining valid from 2019-02-18
Received: 18 September 2018
Accepted: 4 February 2019
First Online: 18 February 2019
Compliance with ethical guidelines
: A. Papachristofilou and T. Finazzi declare that they have no competing interests.
: This article does not contain any studies with human participants or animals performed by any of the authors.