M. S. Illarionova
Chuvash State University named after I. N. Ulyanov
Russian Federation

K. Y. Ivanova
Chuvash State University named after I. N. Ulyanov
Russian Federation

M. V. Kuzmin
Chuvash State University named after I. N. Ulyanov
Russian Federation

A. O. Patianova
Chuvash State University named after I. N. Ulyanov
Russian Federation

V. L. Semenov
Chuvash State University named after I. N. Ulyanov
Russian Federation