Columbia subject headings:
Tariff--Law and legislation--European Economic Community countries.
Tariff--Law and legislation--United States.
Harvard subject headings:
Tariff--Law and legislation--European Economic Community countries.
Tariff--Law and legislation--United States.
Tariff--United States--Law.
Princeton subject headings:
Tariff--Law and legislation--European Economic Community countries.
Tariff--Law and legislation--United States.