N. N. Dobrovolsky
Tula State University
Russian Federation

Dobrovolsky Nikolai Nikolaevich — candidate of physical and mathematical sciences, assistant of the department of applied mathematics and computer science

M. N. Dobrovolsky
Geophysical centre of RAS
Russian Federation

Dobrovolsky Mikhail Nikolaevich — candidate of candidate of physical and mathematical sciences, senior researcher

N. M. Dobrovolsky
Tula State L. N. Tolstoy Pedagogical University
Russian Federation

Dobrovolsky Nikolai Mihailovich — doctor of physical and mathematical sciences, professor, head of the department of algebra, mathematical analysis and geometry

I. N. Balaba
Tula State L. N. Tolstoy Pedagogical University
Russian Federation

Balaba Irina Nikolaevna — doctor of physical and mathematical sciences, assistant professor, professor of the department of algebra, mathematical analysis and geometry

I. Yu. Rebrova
Tula State L. N. Tolstoy Pedagogical University
Russian Federation

Rebrova Irina Yuryevna — candidate of physical and mathematical Sciences, associate professor, dean of the faculty of mathematics, physics and computer science