Grachev, D. I.
Dudylina, A. L.
Titov, V. N.
Ruuge, E. K.
Article History
Received: 25 January 2019
Revised: 12 July 2019
Accepted: 18 July 2019
First Online: 16 December 2019
COMPLIANCE WITH ETHICAL STANDARDS
: <i>Conflict of interests.</i> The authors declare that they have no conflict of interest.
: <i>Statement of compliance with standards of research involving humans as subjects.</i> All procedures performed in studies involving human participants were in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants involved in the study.