Columbia subject headings:
Agriculture--Mexico--Congresses.
Mexico--Economic conditions--Congresses.
Mexico--Emigration and immigration--Congresses.
Mexico--Social conditions--Congresses.
Regionalism--Mexico--Congresses.
Water-supply--Mexico--Congresses.
Harvard subject headings:
Mexico--Social conditions.
Regional economics--Mexico.
Princeton subject headings:
Agriculture--Mexico--Congresses.
Mexico--Economic conditions--Regional disparities--Congresses.
Mexico--Emigration and immigration--Congresses.
Mexico--Social conditions--Congresses.
Regionalism--Mexico--Congresses.
Water-supply--Mexico--Congresses.