Blau, J. et al. 2018. A new fossiliferous site of Lower Liassic (Upper Sinemurian) marine sediments from the southern Sierra Madre Oriental (Puebla, Mexico): ammonite fauna, biostratigraphy, and description of Ectocentrites hillebrandti new species. Revista Mexicana de Ciencias Geológicas. 25, 3 (Jan. 2018), 402–407.