Funding for this research was provided by:
Adam Mickiewicz University in Poznan
Text and Data Mining valid from 2020-02-08
Received: 22 May 2019
Accepted: 27 January 2020
First Online: 8 February 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: The funding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; and in the decision to publish the results.