Asenjo, Conrado F., and Evangelina Recio. “Methionine and Cystine in Puerto Rican Institutional Dishes”. The Journal of Agriculture of the University of Puerto Rico 46, no. 4 (October 1, 1962): 350–359. Accessed November 23, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/12355.