RT Journal Article SR Electronic T1 A Method of Study of the Pulmonary Circulation in Finger Clubbing JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 313 OP 320 DO 10.1136/thx.12.4.313 VO 12 IS 4 A1 Cudkowicz, L. A1 Wraith, D. G. YR 1957 UL http://thorax.bmj.com/content/12/4/313.abstract AB