title: A comparison of oxytetracycline with doxycycline in the winter chemoprophylaxis of chronic bronchitis.
mesh_terms: D000368:Aged; D001991:Bronchitis / Q000188:drug therapy*; D002908:Chronic Disease; D004318:Doxycycline / Q000627:therapeutic use*; D006801:Humans; D008875:Middle Aged; D010118:Oxytetracycline / Q000627:therapeutic use*; D014508:Urea / Q000097:blood
chemical_list: D014508:Urea; D004318:Doxycycline; D010118:Oxytetracycline