Lugo-López, M. A., & Abrams, R. (1981). High Yields of Non-fertilized Protein-rich Pigeon Peas on Tropical Soils of Low Inherent Fertility of Puerto Rico: An Explanation of a Paradox. The Journal of Agriculture of the University of Puerto Rico, 65(1), 21–28. https://doi.org/10.46429/jaupr.v65i1.7558