Silva-Mora, Luis. “Volcanic Geology and Preliminary Chemical Character of the Rocks of the Tula-Polotitlán Region, States of Hidalgo, Mexico and Querétaro, México”. Revista Mexicana De Ciencias Geológicas, vol. 14, no. 1, Jan. 2019, pp. 50-77, https://rmcg.unam.mx/index.php/rmcg/article/view/1126.