U.S. Department of Health and Human Services Web Site
http://www.hhs.gov/faq/technical/418.html

DEA:
http://www.usdoj.gov/dea/concern/concern.htm

MedlinePlus:
http://www.nlm.nih.gov/medlineplus/copyright.html http://www.nlm.nih.gov/medlineplus/linking.html#graphics

Drug Abuse and Substance Abuse Information Partnership For a Drugfree America: http://www.drugfree.org/

The National Institute on Drug Abuse (NIDA)
(part of the National Institutes of Health (NIH)):
http://www.drugabuse.gov/drugpages.html