* "Photographic Documentation of Monuments with Epi-Olmec Script/Imagery" at Foundation for the Advancement of Mesoamerican Studies, Inc. (FAMSI), accessed January 2008.
* Pérez de Lara, Jorge and John Justeson «Photographic Documentation of Monuments with Epi-Olmec Script/Imagery» at Foundation for the Advancement of Mesoamerican Studies, Inc. (FAMSI), accessed January 2008.