Samuels, G., S. Alers-Alers, and G. C. Jackson. “Influence of Fertilizers on Yields of Pineapples on a Coto Clay”. The Journal of Agriculture of the University of Puerto Rico 42, no. 1 (January 1, 1958): 12–26. Accessed December 22, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/12592.