Boyce, D. S. “The Effect of Various Processing Methods on Ease of Removal of More Than Half the Silver Skin from Green Coffee Beans”. The Journal of Agriculture of the University of Puerto Rico 43, no. 2 (April 1, 1959): 128–131. Accessed March 28, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/12550.