Columbia subject headings:
Intervention (International law)
United States--Foreign relations--1961-1963.
United States--Foreign relations--1963-1969.
Vietnam War, 1961-1975.
Harvard subject headings:
Intervention (International law)
United States--Foreign relations--1961-1963.
Vietnam War, 1961-1975.
Princeton subject headings:
Intervention (International law)
United States--Foreign relations--1961-.
Vietnam War, 1961-1975.