RT Journal Article SR Electronic T1 Workplace smoking policy and changes in smoking behaviour in California: a suggested association JF Tobacco Control JO Tob Control FD BMJ Publishing Group Ltd SP 36 DO 10.1136/tc.4.1.36 VO 4 IS 1 A1 C. A. Patten A1 E. Gilpin A1 S. W. Cavin A1 J. P. Pierce YR 1995 UL http://tobaccocontrol.bmj.com/content/4/1/36.abstract AB