Etayo Serna, F. (1964) “Faunas position in the Colombian Cretaceous deposits and their value in their chronological subdivision”, Boletín de Geología, (16-17), pp. 5–142. Available at: https://revistas.uis.edu.co/index.php/revistaboletindegeologia/article/view/5783 (Accessed: 17 May 2024).