Columbia subject headings:
Canada--Dependency on the United States.
Canada--Foreign economic relations--United States.
Canada--Politics and government.
United States--Foreign economic relations--Canada.
Harvard subject headings:
Canada--Dependency on the United States.
Canada--Foreign economic relations--United States.
Canada--Politics and government.
United States--Foreign economic relations--Canada.
Princeton subject headings:
Canada--Dependency on the United States.
Canada--Foreign economic relations--United States.
Canada--Politics and government.
United States--Foreign economic relations--Canada.