Gogichaishvili, A., Martin–del–Pozo, A. L., Urrutia–Fucugauchi, J. y Soler–Arechalde, A. M. (2007) «Human Footprints found in Central Mexico could be at least 40,000 years old», Geofísica Internacional, 46(1), pp. 86–87. doi: 10.22201/igeof.00167169p.2007.46.1.2154.