1. Analytical Methods for Atomic Absorption Spectrophotometry. 1976. Perkin-Elmer. Norwalk, CT.
2. Association of Official Agricultural Chemists. 1975. Methods of analysis. 12th ed. Washington, DC.
3. The colorimetric determination of lactic acid in biological material;Barker;J. Biol. Chem.,1941
4. An interlaboratory experiment comparing conventional and semi-automated fiber analyses for use in the calibration of NIR reflectance spectrometers;Barton,1982
5. In vitro dry matter and organic matter digestion;Barnes,1970