Columbia subject headings:
Communist trials--United States.
Internal security--United States.
Security clearances--United States.
Trials (Political crimes and offenses)--United States.
United States--Politics and government--1945-1953.
Harvard subject headings:
Communist trials--United States.
Internal security--United States
Internal security--United States.
Trials (Political crimes and offenses)--United States
United States--Politics and government--1945-1953.
Princeton subject headings:
Communist trials--United States.
Internal security--United States.
Loyalty oaths--United States.
Security clearances--United States.
Trials (Political crimes and offenses)--United States.
United States--Politics and government--1945-1953.