I.S. Zamulin - Post-graduate Student, Katanov Khakass State University, Abakan. E-mail: zamulin_ivan@mail.ru
S.L. Gafner - Dr.Sc. (Phys.-Math.), Professor, Katanov Khakass State University, Abakan. E-mail: sgafner@khsu.ru sgafner@rambler
L.V. Redel - Ph.D. (Phys.-Math.), Associate Professor, Katanov Khakass State University, Abakan. Е-mail: lredel@khsu.ru
Yu.Ya. Gafner - Dr.Sc. (Phys.-Math.), Professor, Head of Department, Katanov Khakass State University, Abakan. Е-mail: ygafner@khsu.ru

S.L. Gafner, L.V. Redel, J.J. Gafner