Kirkland, James I., and Martha Carolina Aguillón-Martínez. “Schizorhiza: A Unique Sawfish Paradigm from the Difunta Group, Coahuila, Mexico”. Revista Mexicana De Ciencias Geológicas, vol. 19, no. 1, June 2018, pp. 16-24, https://rmcg.unam.mx/index.php/rmcg/article/view/982.