Funding for this research was provided by:
Scientific Grant Agency of the Ministry of Education of the Slovak Republic and the Slovak Academy of Sciences (VEGA 2/0004/18)
Text and Data Mining valid from 2019-10-28
Received: 5 August 2019
Revised: 14 October 2019
Accepted: 19 October 2019
First Online: 28 October 2019
Compliance with ethical standards
: All authors declare that they have no conflict of interest.
: This article does not contain any studies with human or animal subjects.