Ball, D.M.; C.S. Hoveland; G.D. Lacefield. 2007. Southern Forages. Fourth Edition; Appendix A.27.: 298.
Barnes, Robert F.; C. Jerry Nelson; Michael Collins; Kenneth J. Moore. 2003. Forages: An Introduction to Grassland Agriculture. Vol.1; Sixth Edition: 370-373.
Lewis, Lon D. 1996. Feeding and Care of the Horse. Second Edition: 20-28.
Schroeder, J.W. 1994. Interpreting Forage Analysis. North Dakota State University Agriculture. AS-1080. http://www.ag.ndsu.edu/pubs/plantsci/hay/r1080w.htm.
Ward, Marcy; Greg Lardy. 2005. Beef Cattle Mineral Nutrition. North Dakota State University Agriculture. AS-1287. http://www.ag.ndsu.edu/pubs/ansci/beef/as1287w.htm.