Columbia subject headings:
Harvard subject headings:
Hydraulic engineering--Mexico--Mexico, Valley of--History.
Hydraulic engineering--Mexico--Mexico, Valley of.
Indians of Mexico--Agriculture--Mexico--Mexico, Valley of.
Indians of Mexico--Mexico--Mexico, Valley of--Antiquities
Irrigation farming--Mexico--Mexico, Valley of.
Mexico, Valley of (Mexico)--Antiquities.
Princeton subject headings:
Human ecology--Mexico.
Human geography--Mexico.
Mexico--Civilization.