Langenheim JH. Late paleozoic and early mesozoic plant fossils from the Cordillera Oriental of Colombia and correlation of the Giron Formation. Bol.geol. [Internet]. 1 de enero de 1960 [citado 6 de marzo de 2025];8(1-3):95-132. Disponible en: https://revistas.sgc.gov.co/index.php/boletingeo/article/view/371