Irkutsk DeminYuryA.Pedagogical Institute of the Irkutsk State University, 8 Nizhnyaya Naberezhnaya St., Irkutsk 664011, Russiayademin1980@yandex.ru Read more about Yury A. Demin MakeevaSvetlanaB.Irkutsk State University, 1 Lenina St., Irkutsk 664003, Russiamsbmag9581@yandex.ru Read more about Svetlana B. Makeeva