Columbia subject headings:
Mexico--Economic conditions.
Mexico--Relations--Spain.
Mexico--Social conditions.
Spain--Colonies--America.
Spain--Relations--Mexico.
Harvard subject headings:
Mexico--Economic conditions.
Mexico--Relations--Spain.
Mexico--Social conditions.
Spain--Colonies--America.
Spain--Relations--Mexico.
Princeton subject headings:
Mexico--Economic conditions.
Mexico--Relations--Spain.
Mexico--Social conditions.
Spain--Colonies--America.
Spain--Relations--Mexico.