TY JOUR TI Development of Motivation Sphere in 14- and 15-Year-Olds KW personality motivational sphere KW motives of cognitive activity KW motives of educational activity KW social motives KW achievement motivation KW failure avoidance motivation KW sense-forming motives KW interests of adolescents JO Bulletin of Kemerovo State University. Series: Humanities and Social Sciences AU Mikhailova, M.S. AU Shamovskaya, T.V. PY 2021 IS 5 PB Kemerovo State University