S. A., X. Soviet Law Enforcement Agencies (Hrk, Revolutionary Tribunal, Special Department, ChK, GPU, OGPU "Troika", "Five"). European Journal of Life Safety and Stability (2660-9630), [S. l.], v. 12, p. 350-354, 2021. Disponível em: http://ejlss.indexedresearch.org/index.php/ejlss/article/view/325. Acesso em: 5 oct. 2025.