1. Belitz, H.-D., & Grosch, W. (1992). Lehrbuch der Lebensmittelchemie. Berlin/Heidelberg/New York: Springer Verlag.
2. Clark, R. J. H., & Hester, R. E. (1986). Spectroscopy of biological systems. In Advances in Spectroscopy (Vol. 13). Chichester, Sussex: J. Wiley.
3. Codex Alimentarius Commission: Code of principles—concerning milk and milk products; Art. 1.1 and 1.2.
4. Demchenko, A. P. (1981). Ultraviolet Spectroscopy of Proteins. Berlin/Heidelberg/New York: Springer Verlag.
5. High performance liquid chromatography of whey proteins;Diossady;Milchwissenschaft,1980