Columbia subject headings:
United States--Foreign relations--1969-1974.
United States--Foreign relations--1974-1977.
United States--Foreign relations--1977-1981.
Vietnam War, 1961-1975--Influence.
Harvard subject headings:
United States--Foreign relations--1969-1974.
United States--Foreign relations--1974-1977.
United States--Foreign relations--1977-1981.
Vietnam War, 1961-1975--Influence
Princeton subject headings:
United States--Foreign relations--1969-1974.
United States--Foreign relations--1974-1977.
United States--Foreign relations--1977-1981.
Vietnam War, 1961-1975--Influence.