00495naa#a2200169#i#450# EN\INFRA-M\bibl\3224 20250128131445.2 2587-9111 20140617b2014####ek#y0engy0150####ca RUS RU Formalizing Economic Tasks Research Based on State-Variable Approach Journal article Moscow INFRA-M Academic Publishing LLC. 2014 4 с. Journal article local Grishina Svetlana naukaru.ru