http://wilstar.com/caffeine.htm

http://www.energyfiend.com/the-caffeine-database/

http://lds.about.com/library/weekly/aa121202b.htm

http://www.ameribev.org/industry-issues/healthy-balanced-diet/beverage-ingredients/caffeine/index.aspx

http://www.kidshealth.org/teen/drug_alcohol/drugs/caffeine.html

http://en.wikipedia.org/wiki/Caffeine

http://www.marchofdimes.com/pnhec/159_816.asp

http://www.blackwell-synergy.com/doi/abs/10.1111/j.1750-3841.2007.00414.x?journalCode=jfds

http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2621.1983.tb14888.x?journalCode=jfds