Davis Eric M, Ramratnam Sima K, Spahr Jonathan E, Champion Hunter C
Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Ann Am Thorac Soc. 2013 Jun;10(3):261-3. doi: 10.1513/AnnalsATS.201303-041OT.