00530naa#a2200169#i#450# EN\\bibl\111672 20260217175809.2 2712-7516 20260123b2026####ek#y0engy0150####ca RU Portfolio block as a business diversification tool for a transport company Journal article Moscow ITBO University 2026 0 с. Journal article local Управление экономикой. 338.24 Avilov Nikita Mikhailovich zhpi.ru