Azofeifa, J., and R. Barrantes. “Genetic Variation in the Bribri and Cabecar Amerindians from Talamanca, Costa Rica”. Revista De Biología Tropical, vol. 39, no. 2, Nov. 1991, pp. 249–253, https://revistas.ucr.ac.cr/index.php/rbt/article/view/24869.