Columbia subject headings:
Non-tariff trade barriers--United States.
Tariff--United States.
United States--Foreign economic relations.
Harvard subject headings:
Foreign trade regulation--United States.
United States--Commercial policy.
United States--Economic policy--1971-1981.
United States--Economic policy--1981-1993.
United States--Economic policy.
Princeton subject headings:
Tariff--United States.
United States--Commercial policy.
United States--Economic policy.
United States--Foreign economic relations.