Funding for this research was provided by:
Narodowe Centrum Nauki (OPUS NCN 2015/17/B/NZ5/01357 to BAN)
Text and Data Mining valid from 2018-04-23
Received: 23 January 2018
Accepted: 11 April 2018
First Online: 23 April 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.
: Not applicable.