Langenheim, Jean H. «Late Paleozoic and Early Mesozoic Plant Fossils from the Cordillera Oriental of Colombia and Correlation of the Giron Formation». Boletín Geológico 8, no. 1-3 (enero 1, 1960): 95–132. Accedido marzo 6, 2025. https://revistas.sgc.gov.co/index.php/boletingeo/article/view/371.