Columbia subject headings:
Boundaries--Social aspects--Canada.
Canada--Boundaries--United States.
United States--Boundaries--Canada.
Harvard subject headings:
Boundaries--Social aspects--Canada.
Canada--Boundaries--United States.
United States--Boundaries--Canada.
Princeton subject headings:
Boundaries--Social aspects--Canada.
Canada--Boundaries--United States.
Canada--Civilization.
United States--Boundaries--Canada.