Caro Costas, Rubén, Elvin Boneta, and Servando Silva. “Effect of Various Cultural Practices on Yields of Yams in Puerto Rico”. The Journal of Agriculture of the University of Puerto Rico 52, no. 4 (October 1, 1968): 356–361. Accessed April 19, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/11494.