Belgorod GoncharukYaroslavAlexeyevich Belgorod State National Research University, Student st., 14, Belgorod, Belgorod region, 308007goncharuk_ya@bsu.edu.ru Read more about Goncharuk Yaroslav Alexeyevich VolkovaО.А. Belgorod State National Research University, Student st., 14, Belgorod, Belgorod region, 308007volkovaoa@rambler.ru Read more about Volkova О. А.