Velez-Santiago, J., and J. A. Arroyo-Aguilu. “Nitrogen Fertilization and Cutting Frequency, Yield and Chemical Composition of Five Tropical Grasses”. The Journal of Agriculture of the University of Puerto Rico 67, no. 2 (April 1, 1983): 61-69. Accessed January 26, 2022. https://revistas.upr.edu/index.php/jaupr/article/view/7694.