Vicente Chandler, José, Elvin Boneta, Fernando Abruña, and Jacinto Figarella. “Effects of Clean and Strip Cultivation, and of Mulching With Grass, Coffee Pulp, and Black Plastic, on Yields of Intensively Managed Coffee in Puerto Rico”. The Journal of Agriculture of the University of Puerto Rico 53, no. 2 (April 1, 1969): 124–131. Accessed November 22, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/11168.