00507naa#a2200169#i#450# EN\INFRA-M\bibl\5640 20250107144915.2 1998-0744 20150417b2015####ek#y0engy0150####ca RUS RU On Constructing the System of Elective Math Courses in Subject Oriented Education Journal article Moscow INFRA-M Academic Publishing LLC. 2015 9 с. Journal article local Mardakhaeva Elena zh-szf.ru