Columbia subject headings:
Espionage, Russian--History.
Intelligence service--Russia--History.
Russia. Okhrannyi︠a︡ otdi︠e︡lenīi︠a︡.
Secret service--Russia--History.
Harvard subject headings:
Espionage--Russia--History.
Intelligence service--Russia--History.
Russia. Okhrannyi︠a︡ otdi︠e︡lenīi︠a︡
Secret service--Russia--History
Princeton subject headings:
Intelligence service--Russia--History.
Russia. Okhrannyi︠a︡ otdi︠e︡lenīi︠a︡--History.
Secret service--Russia--History.