00725naa#a2200181#i#450# EN\\bibl\111769 20260115043450.4 1994-4683 20250913b2025####ek#y0engy0150####ca RU Development of speed-strength qualities in schoolchildren in athletics classes under the program of additional education Journal article Moscow National State University of Physical Education, Sports and Health named after P.F. Lesgaft 2025 4 с. Journal article local Дополнительное обучение. 371.398 Prohorenko Andrey Aleksandrovich Antonov Andrey Vasil'evich uchzapiski.lesgaft.spb.ru