Research & Education JFS ArticlesAAFS ConnectConference ProceedingsReference Series LibraryInternational Educational Outreach ProgramUrinary Fentanyl and Norfentanyl During Application of Duragesic Transdermal PatchesPresenting section:Toxicology2004Poklis, Alphonse, Richmond VA; Backer, Ronald C., Midland TXView the paperToxicology