Columbia subject headings:
Harvard subject headings:
Police--Russia.
Russia--History--Nicholas II, 1894-1917.
Russia. Okhrannyi︠a︡ otdi︠e︡lenīi︠a︡
Secret service--Russia.
Princeton subject headings:
Intelligence service--Russia--History.
Political crimes and offenses--Russia--History.
Russia. Departament polit︠s︡īi--History.
Secret service--Russia--History.