Columbia subject headings:
Harvard subject headings:
Espionage, Soviet--United States--History--20th century.
Espionage, Soviet--United States--History.
Soviet Union. Komitet gosudarstvennoĭ bezopasnosti--History.
Princeton subject headings:
Espionage, Soviet--United States--History--20th century.
Soviet Union. Komitet gosudarstvennoĭ bezopasnosti--History.