RT Journal Article SR Electronic T1 The Difficulty of Measuring the Measurable JF Respiratory Care FD American Association for Respiratory Care SP 1155 OP 1156 DO 10.4187/respcare.03380 VO 59 IS 7 A1 Perren, Andreas A1 Merlani, Paolo YR 2014 UL http://rc.rcjournal.com/content/59/7/1155.abstract AB