1. Code of Federal Regulations (2009a). Percentage juice declaration for foods purporting to be beverages that contain fruit or vegetable juice. Food and Drug Administration. 21 CFR 101.30a. Revised April 1, 2009.
2. Code of Federal Regulations (2009b). Beverages that contain fruit or vegetable juice. Food and Drug Administration. 21 CFR 102.33g. Revised April 1, 2009.
3. Code of Federal Regulations (2009c). Antioxidant nutrient content claims. Food and Drug Administration. 21 CFR 101.54g. Revised April 1, 2009.
4. On tyrosine and tryptophane determinations in proteins;Folin;Journal of Biological Chemistry,1927
5. Nachweis von Masthilfsmitteln in Lebensmitteln;Gunther;Fresenius Zeitschrift Fur Analytische Chemie,1978