RT Journal Article SR Electronic T1 Mixed progress against lung cancer JF Tobacco Control JO Tob Control FD BMJ Publishing Group Ltd SP 223 OP 226 DO 10.1136/tc.7.3.223 VO 7 IS 3 A1 Michael J Thun YR 1998 UL http://tobaccocontrol.bmj.com/content/7/3/223.abstract AB