RT Journal Article SR Electronic T1 Give me a sign, any sign JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 737 OP 738 DO 10.1136/thx.2008.107409 VO 64 IS 9 A1 Peter J Mazzone YR 2009 UL http://thorax.bmj.com/content/64/9/737.abstract AB