RT Journal Article SR Electronic T1 Secondary genetic factors in cystic fibrosis lung disease JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 446 OP 446 DO 10.1136/thorax.55.6.446 VO 55 IS 6 A1 RAVI MAHADEVA A1 DAVID A LOMAS YR 2000 UL http://thorax.bmj.com/content/55/6/446.abstract AB