RT Journal Article SR Electronic T1 Volume doubling time for lung cancer screening JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 79 OP 79 DO 10.1136/thoraxjnl-2013-203448 VO 69 IS 1 A1 Colclough, James M YR 2014 UL http://thorax.bmj.com/content/69/1/79.abstract AB