TY - JOUR T1 - Butting out in Canada: five down, eight to go JF - Canadian Medical Association Journal JO - CMAJ SP - 558 LP - 558 DO - 10.1503/cmaj.1041400 VL - 171 IS - 6 AU - Bradford Mackay Y1 - 2004/09/14 UR - http://www.cmaj.ca/content/171/6/558.abstract ER -