Pastor Rodríguez, Juan, and Pablo Landrau, Jr. “Essentials of Successful Potato Culture in Puerto Rico”. The Journal of Agriculture of the University of Puerto Rico 40, no. 3 (July 1, 1956): 157–170. Accessed April 25, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/13797.