Columbia subject headings:
Automobile industry and trade--Canada.
Automobile industry and trade.
Canada--Commercial treaties.
Duty-free importation of automobiles--Canada.
Duty-free importation of automobiles--United States.
United States--Commercial treaties.
Harvard subject headings:
Duty-free importation of automobiles--Canada.
Duty-free importation of automobiles--United States.
Princeton subject headings:
Duty-free importation of automobiles--Canada.
Duty-free importation of automobiles--United States.