Langenheim, J. H. (1959). Preliminary Notes on Plant Fossils from Late Paleozoic and Early Mesozoic Rocks in the Cordillera Oriental of Colombia. Boletín De Geología, (3), 51–53. Recuperado a partir de https://revistas.uis.edu.co/index.php/revistaboletindegeologia/article/view/4003