Irizarry, H., J. Howard Ellison, and Portia Orton. “Inheritance of Persistent-Green Color in Asparagus Officinalis, L”. The Journal of Agriculture of the University of Puerto Rico 51, no. 1 (January 1, 1967): 71–76. Accessed May 5, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/11221.