TY JOUR TI Experience in applying the biofeedback method to assess the current psychological state of students during the educational process KW biofeedback method KW current psychological state KW cardiorhythmogram KW emotional sphere KW self-study JO Living psychology AU Ababkova, M.Y. AU Leonteva, V.L. PY 2018 IS 5 PB Ltd Radomir-M+