00589naa#a2200157#i#450# EN\FGKOU VO SPBU MVD ROSSII\bibl\104653 20251225211824.4 2227-7226 20251223b2025####ek#y0engy0150####ca RU Role and importance of confidential assistance in operational investigative activities Journal article St. Petersburg SAINT-PETERSBURG UNIVERSITY OF THE MINISTRY OF INTERNAL AFFAIRS OF THE RUSSIAN FEDERATION 2025 7 с. Journal article local Popov Sergey Viktorovich vestnikspbmvd.ru