Columbia subject headings:
Boundaries--Congresses.
Culture diffusion--Congresses.
International cooperation--Congresses.
International economic relations--Congresses.
Harvard subject headings:
Boundaries--Congresses.
Culture diffusion--Congresses.
International cooperation--Congresses
International economic relations--Congresses
Princeton subject headings:
Boundaries--Congresses.
United States--Boundaries--Canada--Congresses.
United States--Boundaries--Mexico--Congresses.