Columbia subject headings:
Harvard subject headings:
Espionage, Soviet--United States--History.
Espionage--United States--History--20th century.
Soviet Union. Glavnoe razvedyvatelʹnoe upravlenie
United States. Federal Bureau of Investigation
Princeton subject headings:
Espionage, Soviet--United States--History--20th century.
Espionage--United States--History--20th century.
Soviet Union. Glavnoe rezvedyvatelʹnoe upravlenie.
United States. Federal Bureau of Investigation