00718naa#a2200169#i#450# EN\\bibl\109808 20251223203054.2 1994-4683 20250913b2025####ek#y0engy0150####ca RU Motor activity of schoolchildren aged 11-13 years old out of course time Journal article Moscow National State University of Physical Education, Sports and Health named after P.F. Lesgaft 2025 3 с. Journal article local Философские и научно-теоретические основы физической культуры и спорта. 796.011 Eliseeva Tatyana Aleksandrovna uchzapiski.lesgaft.spb.ru