Julivert, Manuel. “Stratigraphy and Sedimentology of the Lower Part of the Guaduas Formation to the South of the Sabana De Bogotá”. Boletín de Geología, no. 12 (April 25, 1963): 85–99. Accessed May 18, 2024. https://revistas.uis.edu.co/index.php/revistaboletindegeologia/article/view/5732.