Columbia subject headings:
Canada--Commercial treaties.
Free trade--Canada.
Free trade--Mexico.
Free trade--North America.
Free trade--United States.
Mexico--Commercial treaties.
North America--Commercial treaties--History.
North American Free Trade Agreement
North American Free Trade Agreement--History.
United States--Commercial treaties.
Harvard subject headings:
Free trade--Canada
Free trade--Mexico
Free trade--North America
Free trade--United States
North America--Commercial treaties--History.
North American Free Trade Agreement--History.
Princeton subject headings:
Canada. Treaties, etc. 1992 Oct. 7--History.
Free trade--Canada.
Free trade--Mexico.
Free trade--North America.
Free trade--United States.
North America--Commercial treaties--History.