Lomonte, Bruno, César Bonilla, José A. Gené, Eugenia Mata, and Jorge Alvarado. 1987. “Serum Immunoglobulin Levels in Cabécar and Guaymí Indians in Southeastern Costa Rica”. Revista De Biología Tropical 35 (2):339–340. https://revistas.ucr.ac.cr/index.php/rbt/article/view/24112.