Columbia subject headings:
Commerce--Bibliography.
Reciprocity (Commerce)--Bibliography.
Tariff--United States--Bibliography.
United States--Commerce--Bibliography.
Harvard subject headings:
Commerce--Bibliography
Reciprocity (Commerce)--Bibliography.
Tariff--United States--Bibliography.
United States--Commerce--Bibliography.
Princeton subject headings:
Commerce--Bibliography.
Reciprocity (Commerce)--Bibliography.
Tariff--United States--Bibliography.
United States--Commerce--Bibliography.