00598naa#a2200169#i#450# EN\INFRA-M\bibl\126108 20260818101305.2 1998-0728 20260618b2026####ek#y0engy0150####ca RU Why Extracurricular Activities Are Becoming a Factor in Overloading Elementary Schoolchildren Journal article Moscow INFRA-M Academic Publishing LLC. 2026 6 с. Journal article local Первая ступень обучения. Начальная школа. 373.3 Artyuhova I. S. naukaru.ru