Avatar-Based Learning and Teaching as a Concept of New Perspectives in Online Education in Post-Soviet Union Countries: Theory, Environment, Approaches, Tools. - Vardan Mkrttchian; Dina Kharicheva; Ekaterina Aleshina; Svetlana Panasenko; Yulia Vertakova; Leyla Gamidullaeva; Mikhail Ivanov; Vsevolod S. Chernyshenko (Int. J. Virtual Pers. Learn. Environ., 2020)