RT Journal Article SR Electronic T1 Varenicline for 4 weeks prior to target quit date reduces prequit date smoking and increases 12-week abstinence JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 96 OP 97 DO 10.1136/ebmed.2011.100147 VO 17 IS 3 A1 Gina Daubney Garrison YR 2012 UL http://ebm.bmj.com/content/17/3/96.abstract AB