Ortiz-Hernández, Luis Enrique, et al. “Petrographic and Geochemical Characteristics of Upper Aptian Calc-Alkaline Volcanism in San Miguel De Allende, Guanajuato State, Mexico”. Revista Mexicana De Ciencias Geológicas, vol. 19, no. 2, June 2018, pp. 81-90, https://rmcg.unam.mx/index.php/rmcg/article/view/976.