P. Horn, Sally. “Prehistoric Fires in the Chirripó Highlands of Costa Rica: Sedimentary Charcoal Evidence”. Revista de Biología Tropical 37, no. 2 (November 1, 1989): 139–148. Accessed November 30, 2024. https://revistas.ucr.ac.cr/index.php/rbt/article/view/23523.