Abrams, R., D. Walker, and M. Rico Ballester. “Effect of Pesticides on the Yield of Some Vegetable Crops in the Isabela Area of Puerto Rico”. The Journal of Agriculture of the University of Puerto Rico 46, no. 1 (January 1, 1962): 1–8. Accessed December 22, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/12287.