title: Contingent reinforcement of benzodiazepine-free urines from methadone maintenance patients.
mesh_terms: D000328:Adult; D001569:Benzodiazepines / Q000008:administration & dosage / Q000652:urine*; D006801:Humans; D008297:Male; D008691:Methadone / Q000627:therapeutic use*; D009293:Opioid-Related Disorders / Q000534:rehabilitation*
chemical_list: D001569:Benzodiazepines; D008691:Methadone