title: Comparisons of hypnotic drugs.
mesh_terms: D002986:Clinical Trials as Topic; D006801:Humans; D010634:Phenobarbital / Q000008:administration & dosage*; D010919:Placebos; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy*
chemical_list: D010919:Placebos; D010634:Phenobarbital