Columbia subject headings:
Evidence, Documentary--United States--Congresses.
Government litigation--United States--Congresses.
Security classification (Government documents)--United States--Congresses.
Harvard subject headings:
Evidence, Documentary--United States--Congresses.
Government information--United States--Congresses.
Government litigation--United States--Congresses.
National security--United States--Congresses
Security classification (Government documents)--United States--Congresses.
Princeton subject headings:
Evidence, Documentary--United States--Congresses.
Government litigation--United States--Congresses.
Security classification (Government documents)--United States--Congresses.