Columbia subject headings:
Canada--Foreign economic relations--United States.
Free trade--Canada.
Free trade--United States.
United States--Foreign economic relations--Canada.
Harvard subject headings:
Canada--Foreign economic relations--United States.
Canada--Foreign relations--United States.
Free trade--Canada
Free trade--Political aspects--Canada.
Free trade--Social aspects--Canada.
Free trade--United States
United States--Foreign economic relations--Canada.
United States--Foreign relations--Canada.
Princeton subject headings:
Canada--Foreign relations--United States.
Free trade--Canada.
Free trade--Political aspects--Canada.
Free trade--Social aspects--Canada.
Free trade--United States.
United States--Foreign relations--Canada.