Klopfenstein, Terry, Roselina Angel, Gary L. Cromwell, Galen E. Erickson, Danny G. Fox, Carl Parsons, Larry D. Satter, and Alan L. Sutton. “Animal Diet Modification To Decrease The Potential For Nitrogen And Phosphorus Pollution”. Council for Agricultural Science and Technology (CAST) (July 16, 2002). Accessed July 1, 2026. https://publications.cast-science.org/CAST/article/view/182.