00473naa#a2200169#i#450# EN\INFRA-M\bibl\3668 20251214152829.7 1998-0728 20141017b2014####ek#y0engy0150####ca RUS RU Once Again оn Electronic Textbooks Journal article Moscow INFRA-M Academic Publishing LLC. 2014 1 с. Journal article local Vinogradova Natalya Fedorovna naukaru.ru