Pérez Escolar, Raúl, and M. A. Lugo López. “Availability of Moisture in Aggregates of Various Sizes in a Typical Ultisol and a Typical Oxisol of Puerto Rico”. The Journal of Agriculture of the University of Puerto Rico 53, no. 2 (April 1, 1969): 113–117. Accessed March 29, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/11166.