00671naa#a2200169#i#450# EN\INFRA-M\bibl\45787 20240723203659.2 1998-1740 20211029b2021####ek#y0engy0150####ca RU Difficulties in Mastering Universal Educational Cognitive Actions of Students in the 6th and 8th grade (Based on the Results of Diagnostic Work) Journal article Moscow INFRA-M Academic Publishing LLC. 2021 9 с. Journal article local Образование. Воспитание. Обучение. Организация досуга. 37 Ambarcumova E. M. naukaru.ru