RT Journal Article SR Electronic T1 Nearly 85% of tobacco smoke is invisible—a confirmation of previous claims JF Tobacco Control JO Tob Control FD BMJ Publishing Group Ltd SP 429 OP 429 DO 10.1136/tobaccocontrol-2012-050475 VO 22 IS 6 A1 Ivan L Gee A1 Sean Semple A1 Adrian Watson A1 Andrea Crossfield YR 2013 UL http://tobaccocontrol.bmj.com/content/22/6/429.abstract AB