00827naa#a2200205#i#450# EN\\bibl\109510 20260206202703.5 1994-4683 20250913b2025####ek#y0engy0150####ca RU Features of adaptation of younger adolescents during the transition from primary school to basic school general education Journal article Moscow National State University of Physical Education, Sports and Health named after P.F. Lesgaft 2025 3 с. Journal article local Педагогическая психология. 37.015.3 Stepchenko Tat'yana Aleksandrovna Savin Aleksandr Vyacheslavovich Seraya Galina Vladimirovna Simukova Svetlana Vasil'evna uchzapiski.lesgaft.spb.ru