Lugo López, M. A., M. B. Martínez, and A. R. Riera. “Morphological and Physicochemical Properties of Various Tropical Soils from East-Central Puerto Rico”. The Journal of Agriculture of the University of Puerto Rico 36, no. 2 (April 1, 1952): 167–178. Accessed December 22, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/12797.