1. Blainey, Marc G. 2007 Surfaces and Beyond: The Political, Ideological, and Economic Significance of Ancient Maya Iron-Ore Mirrors . Unpublished M.A. thesis, Department of Anthropology, Trent University, Peterborough.
2. López Luján, Leonardo , Cobean, Robert H. , and Mastache, Alba Guadalupe 1995 Xochicalco y Tula. Consejo Nacional para la Cultura y las Artes, Mexico City.