Pérez Escolar, R. and Lugo López, M. A. (1969) “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(2), pp. 113–117. doi: 10.46429/jaupr.v53i2.11166.