Chemical Characteristics of Obsidian from Archaeological Sites in Western Mexico and the Tequila Source Areav. 4255–270
Trombold, C. D., Luhr, James F., Hasenaka, T., and Glascock, Michael D. 1993. "Chemical Characteristics of Obsidian from Archaeological Sites in Western Mexico and the Tequila Source Area." Ancient Mesoamerica, 4 255–270.