1. AACC (1978). “Approved Methods of the AACC”. 1978 Revisions: Method 32–20. American Association of Cereal Chemists, St. Paul. MN.
2. AOAC (1975). “Official Methods of Analysis”. 12th Ed. Association of Official Analytical Chemists, Washington, D.C.
3. Pasture quality and ruminant nutrition