Abruña, Fernando, Servando Silva, and José Vicente-Chandler. “Effects of Yields, Shade, and Varieties on Size of Coffee Beans”. The Journal of Agriculture of the University of Puerto Rico 50, no. 3 (July 1, 1966): 226–230. Accessed April 26, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/3460.