Badillo-Feliciano, J., and M. A. Lugo-López. “Differential Response of Corn and Sweet Potatoes to Zn Applications in an Oxisol in Northwestern Puerto Rico”. The Journal of Agriculture of the University of Puerto Rico 64, no. 4 (October 1, 1980): 482–488. Accessed December 21, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/10194.