Fernández-Coll, Fred, and Luis Silva-Negrón. “Conventional Versus the Petrifilm Method for the Enumeration of Different Types of Bacteria”. The Journal of Agriculture of the University of Puerto Rico 73, no. 3 (July 1, 1989): 183–187. Accessed April 26, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/6455.