Pérez-López, Agripino, and Rubén D. Reyes. “Effect of Nitrogen and Boron Applications on Carica Papaya L. II. Petiole and Fruit Nutrient Content and N and B Index for Leaf Tissue Analysis”. The Journal of Agriculture of the University of Puerto Rico, vol. 68, no. 1, Jan. 1984, pp. 5-17, doi:10.46429/jaupr.v68i1.7254.