TY - JOUR T1 - First exposure JF - Canadian Medical Association Journal JO - CMAJ SP - 288 LP - 288 DO - 10.1503/cmaj.150291 VL - 188 IS - 4 AU - Bob Sun Y1 - 2016/03/01 UR - http://www.cmaj.ca/content/188/4/288.abstract ER -