Kursk Mironova Diana M. Southwest State University, 94 50 let Oktyabrya St., Kursk 305040, Russia mir-lina@yandex.ru Read more about Mironova Diana M. BurunskyVladimirMarkovich Kursk State University, Russia, 305000, Kursk, Radishev street, 33 vburun@yandex.ru Read more about Burunsky Vladimir Markovich KrivolapovaElenaMikhailovna Kursk State University, Russia, 305000, Kursk, Radishev street, 33 elena_vroblevska@mail.ru Read more about Krivolapova Elena Mikhailovna