00554naa#a2200181#i#450# EN\\bibl\88164 20250806034938.3 2074-8183 20171225b2017####ek#y0engy0150####ca RUS RU THE PROBLEM OF CLASSIFICATION OF ELECTRONIC LEARNING SYSTEMS AND VARIANTS FOR ITS SOLUTIONS Journal article Volgograd Volgograd Academy of the Ministry of Internal Affairs of Russia 2017 6 с. Journal article local va-mvd.editorum.ru