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