RT Journal Article SR Electronic T1 Is Extended-Release Guaifenesin No Better Than a Placebo? JF Respiratory Care FD American Association for Respiratory Care SP 788 OP 789 DO 10.4187/respcare.03319 VO 59 IS 5 A1 Oisin J O'Connell YR 2014 UL http://rc.rcjournal.com/content/59/5/788.abstract AB