Funding for this research was provided by:
Ministerstvo školstva, vedy, výskumu a športu Slovenskej republiky (1/0846/18)
Text and Data Mining valid from 2018-08-22
Received: 4 April 2018
Accepted: 17 August 2018
First Online: 22 August 2018
: The authors declare that they have no competing interests.
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