RT Journal Article SR Electronic T1 Pulmonary puzzle JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 353 OP 353 DO 10.1136/thx.2009.129890a VO 65 IS 4 YR 2010 UL http://thorax.bmj.com/content/65/4/353.abstract AB