BARRAGÁN, Ricardo; MAURRASSE, Florentin J-M. R. Lower Aptian (Lower Cretaceous) ammonites from the basal strata of the La Peña Formation of Nuevo León State, northeast Mexico: biochronostratigraphic implications. Revista Mexicana de Ciencias Geológicas, [S. l.], v. 25, n. 1, p. 145–157, 2018. Disponível em: https://rmcg.unam.mx/index.php/rmcg/article/view/677. Acesso em: 15 mar. 2025.