1. Azhar Mohammed Al-Khazali, University of Sumer, College of Basic Education, Department of sciences, Dhi Qar, Iraq; E-mail: azhararach@gmail.com
2. Alexander A. Fomichev, Tomsk State University, Lenina Prospect, 36, Tomsk, 634050, Russia, Altai State University, Lenina Prospect, 61, Barnaul, 656049, Russia; E-mail: a.fomichov@mail.ru