Columbia subject headings:
Espionage--United States.
Intelligence service--United States.
Subversive activities--United States.
United States. Central Intelligence Agency.
Harvard subject headings:
Espionage--United States.
Intelligence service--United States.
Subversive activities--United States
United States. Central Intelligence Agency
Princeton subject headings:
Espionage--United States.
Intelligence service--United States.
Subversive activities--United States.
United States. Central Intelligence Agency