TY - JOUR T1 - Seventy-two hours max JF - Canadian Family Physician JO - Can Fam Physician SP - 246 LP - 246 VL - 54 IS - 2 A2 - , Y1 - 2008/02/01 UR - http://www.cfp.ca/content/54/2/246.1.abstract N2 - ER -