Semidey, Nelson, and Elvin Caraballo. “Chemical Weed Management in Onions (Allium Cepa L.)”. The Journal of Agriculture of the University of Puerto Rico 73, no. 1 (January 1, 1989): 59–65. Accessed April 19, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/6374.