Columbia subject headings:
Developing countries.
United States--Foreign relations--1981-1989.
Vietnam War, 1961-1975--United States.
Harvard subject headings:
Developing countries.
United States--Foreign relations--1981-1989.
United States--Foreign relations--1989-
Vietnam War, 1961-1975--United States
Princeton subject headings:
Developing countries.
United States--Foreign relations--1981-.
Vietnam War, 1961-1975--United States.