TY JOUR TI Analyses of the Features of General Schooling of Russian Younger Schoolchildren in Accordance to the Results of International Research TIMSS-2015 (Mathematics) KW international monitoring study TIMSS KW fourth grade schoolchildren KW Federal state educational standard of primary education KW universal learning activities KW mathematics KW typical difficulties of general educatoin nature. JO Primary Education AU Rydze, O.A. PY 2017 IS 5 PB INFRA-M Academic Publishing LLC.