Barnes, D. K., and R. H. Freyre. “Seed-Production Potential of Tephrosia Vogelii in Puerto Rico”. The Journal of Agriculture of the University of Puerto Rico 53, no. 3 (July 1, 1969): 207–212. Accessed December 22, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/11160.