Lucas, Spencer G., William C. McIntosh, and Carlos Manuel González-León. 2019. “Eocene Ar40-Ar39 Age Data of Supposed Cretaceous Volcanics (Rhyolite Tuff Formation) in Northeastern Sonora, Mexico”. Revista Mexicana De Ciencias Geológicas 13 (2):184-87. https://rmcg.geociencias.unam.mx/index.php/rmcg/article/view/1156.