Nieto-Samaniego, Ángel Francisco, et al. “SHORT NOTE - New Isotopic Ages of the Cenozoic Volcanic Cover of the Southern Central Plateau, Mexico”. Revista Mexicana De Ciencias Geológicas, vol. 13, no. 1, Jan. 2019, pp. 117-22, https://www.rmcg.unam.mx/index.php/rmcg/article/view/1145.