Title: Secrets of the O.G.P.U.
Subjects: Soviet Union. Obʺedinennoe gosudarstvennoe politicheskoe upravlenie, Russian S.F.S.R. Chrezvychaĭnai︠a︡ komissii︠a︡ po borʹbe s kontr-revoli︠u︡t︠s︡ieĭ i sabotazhem