RT Journal Article SR Electronic T1 Reply JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 479 OP 479 DO 10.1136/thx.39.6.479-a VO 39 IS 6 A1 Fitzgerald, MX YR 1984 UL http://thorax.bmj.com/content/39/6/479.2.abstract AB