Córdova-Orellana, Hugo, Salvador Castellanos, and Jorge Bolaños. “Twenty Five Years of System’s Improvement of Corn in Central America: Accomplishments and Strategies Toward the Year 2000.”. Agronomía Mesoamericana 13, no. 1 (1): 73-84. Accessed January 24, 2022. https://revistas.ucr.ac.cr/index.php/agromeso/article/view/13567.