Grigoryev, S. A.
Popova, E. Y.
Article History
Received: 16 May 2019
Revised: 10 June 2019
Accepted: 12 June 2019
First Online: 16 December 2019
COMPLIANCE WITH ETHICAL STANDARDS
: The authors declare no conflict of interests.
: This article contains no research involving human subjects or animals as the research objects.