BIGELOW, Barbara C.; EDGAR, Kathleen J. The UXL Encyclopedia of Drugs & Addictive Substances. [s.l.]: Thomson-Gale, 2006. Dostupné online. ISBN1-4144-0444-1.
brendan-nyhan.com
NYHAN, Brendan. Entertainment Weekly fact-checks Tom Cruise [online]. 2005. Dostupné online.
web.archive.org
GERLACH, Ralf. The History of Methadone [online]. 2004 [cit. 2013-01-01]. Dostupné v archivu pořízeném dne 2012-01-25.