Hewitt, William P.; Winter, Marcus C.; Peterson, David A. (1987). "Salt Production at Hierve El Agua, Oaxaca". American Antiquity. 52 (4): 799–816. doi:10.2307/281388. JSTOR281388.
Doolittle, William E. (July 1995). "Indigenous development of Mesoamerican irrigation". Geographical Review. 85 (3). New York: Geographical Review, Vol. 85, No. 3: 301–323. doi:10.2307/215275. JSTOR215275.
Hewitt, William P.; Winter, Marcus C.; Peterson, David A. (1987). "Salt Production at Hierve El Agua, Oaxaca". American Antiquity. 52 (4): 799–816. doi:10.2307/281388. JSTOR281388.
Doolittle, William E. (July 1995). "Indigenous development of Mesoamerican irrigation". Geographical Review. 85 (3). New York: Geographical Review, Vol. 85, No. 3: 301–323. doi:10.2307/215275. JSTOR215275.