Cedeño-Maldonado, A., and L. C. Liu. “Effect of Two Substituted Urea and Two S-Triazine Type Herbicides on the Photosynthesis of Lemna Perpusilla Torr”. The Journal of Agriculture of the University of Puerto Rico 60, no. 3 (July 1, 1976): 369–374. Accessed March 28, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/10529.