Funding for this research was provided by:
Russian Science Foundation (18-74-10044)
Russian Government Program of Competitive Growth of Kazan Federal University and subsidy allocated to Kazan Federal University for the state assignment in the sphere of scientific activities
Text and Data Mining valid from 2019-03-15
First Online: 15 March 2019
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.