Sotomayor-Ramírez, David, Gustavo Martínez, and Luis J. Olivieri. “Phosphorus Status of Stream Waters in Puerto Rico: 1989-19971”. The Journal of Agriculture of the University of Puerto Rico 85, no. 1-2 (April 1, 2001): 1–15. Accessed November 23, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/3151.