Columbia subject headings:
Harvard subject headings:
Irrigation--Social aspects--Mexico--Tehuacán River Valley.
Land tenure--Mexico--Tehuacán River Valley.
Peasants--Mexico--Tehuacán River Valley.
Tehuacán River Valley (Mexico)--Rural conditions.
Princeton subject headings:
Community development--Mexico--Ajalpan.
Peasants--Mexico--Ajalpan.
Tehuacan region (Mexico)--Rural conditions.