TY JOUR TI The principle of educational variation: support for the diversity of childhood KW childhood KW unity KW diversity KW diversification KW variability KW educational standard KW educational space KW educational program KW freedom KW teacher's self-awareness KW responsibility KW strategy KW quality of education. JO Journal of Pedagogical Studies AU Lykova, I.A. PY 2017 IS 2 PB INFRA-M Academic Publishing LLC.