Columbia subject headings:
Balance of payments--Canada.
Balance of payments--United States.
Canada--Commerce--United States.
United States--Commerce--Canada.
Harvard subject headings:
Balance of payments--Canada.
Balance of payments--United States
Canada--Commerce--United States.
United States--Commerce--Canada.
Princeton subject headings:
Balance of payments--Canada.
Balance of payments--United States.
Canada--Commerce--United States.
United States--Commerce--Canada.