1. U.S. Department of Agriculture, Agricultural Research Service. (2005). USDA National Nutrient Database for Standard Reference, Release 18. Nutrient Data Laboratory, on the World Wide Web, http://www.ars.usda.gov/Services/docs.htm?docid=8964
2. U.S. Department of Agriculture, Agricultural Research Service. (2003). USDA Database for the Flavonoid Content of Selected Foods. Nutrient Data Laboratory, on the World Wide Web: http://www.nal.usda.gov/fnic/foodcomp/Data/Flav/flav.html
3. U.S. Department of Agriculture, Agricultural Research Service. (2004). USDA Database for the Proanthocyanidin Content of Selected Foods. Nutrient Data Laboratory, on the World Wide Web: http://www.nal.usda.gov/fnic/foodcomp/Data/PA/PA.html
4. U.S. Department of Agriculture, Agricultural Research Service. (2004). USDA Database for the Choline Content of Common Foods. Nutrient Data Laboratory, on the World Wide Web: http://www.nal.usda.gov/fnic/foodcomp/Data/Choline/Choline.html
5. U.S. Department of Agriculture, Agricultural Research Service. (2004). USDA National Fluoride Database of Selected Beverages and Foods. Nutrient Data Laboratory, on the World Wide Web: http://www.nal.usda.gov/fnic/foodcomp/Data/Fluoride/Fluoride.html