Columbia subject headings:
Harvard subject headings:
Drinking water--Contamination--Mexico--Balsas River Valley.
Drinking water--Mexico--Balsas River Valley.
Hydrogeology--Mexico--Balsas River Valley.
Water quality management--Mexico--Balsas River Valley.
Water--Distribution--Mexico--Balsas River Valley.
Water--Mexico--Balsas River Valley--Distribution.
Water-supply--Mexico--Balsas River Valley--Management.
Water-supply--Mexico--Balsas River Valley.
Princeton subject headings:
Balsas River Watershed (Mexico)
Water-supply--Mexico--Balsas River Watershed.