Landrau, Jr., P., G. Samuels, and S. Alers-Alers. “The Response of Two Sugarcane Varieties to Fertilizers at Río Piedras, 1954-57”. The Journal of Agriculture of the University of Puerto Rico 43, no. 2 (April 1, 1959): 73–88. Accessed December 22, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/12546.