Improvement of sleep quality by melatonin.
D000368:Aged; D006801:Humans; D008550:Melatonin / Q000008:administration & dosage*; D008875:Middle Aged; D012890:Sleep / Q000187:drug effects*; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy*
D008550:Melatonin