RT Journal Article SR Electronic T1 Electronic cigarettes: pro JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 309 OP 310 DO 10.1136/thoraxjnl-2015-206935 VO 70 IS 4 A1 Britton, John YR 2015 UL http://thorax.bmj.com/content/70/4/309.abstract AB