00640naa#a2200169#i#450# EN\INFRA-M\bibl\43237 20240914170507.6 1998-0728 20210421b2021####ek#y0engy0150####ca RU Mastering by Students of the Second Grades of the Universal Educational Action of Classification Journal article Moscow INFRA-M Academic Publishing LLC. 2021 4 с. Journal article local Образование. Воспитание. Обучение. Организация досуга. 37 Yankovskaya Tat'yana Aleksandrovna naukaru.ru