title: Proficiency testing of drug analysis laboratories.
authors.forename: H G
authors.initials: HG
authors.lastname: McCoy
mesh_terms: D005189:False Positive Reactions; D006801:Humans; D007753:Laboratories / Q000592:standards*; D009294:Narcotics / Q000032:analysis; D015813:Substance Abuse Detection / Q000592:standards*; D014481:United States; D014486:United States Food and Drug Administration; D014482:United States Substance Abuse and Mental Health Services Administration
chemical_list: D009294:Narcotics