Columbia subject headings:
Grijalva River Valley (Mexico)--Economic conditions.
Grijalva River Valley (Mexico)--Environmental conditions.
Grijalva River Valley (Mexico)--History.
Grijalva River Valley (Mexico)--Social conditions.
Physical geography--Mexico--Grijalva River Valley.
Harvard subject headings:
Agriculture--Mexico--Grijalva River Watershed.
Grijalva River Watershed (Mexico)--Environmental conditions.
Human ecology--Mexico--Grijalva River Watershed.
Watershed management--Mexico--Grijalva River Watershed.
Princeton subject headings: