TY - JOUR T1 - Epidemiology for the uninitiated, 5th ed. JF - Canadian Medical Association Journal JO - CMAJ SP - 1191 LP - 1191-a VL - 169 IS - 11 AU - AM Clarfield Y1 - 2003/11/25 UR - http://www.cmaj.ca/content/169/11/1191.2.abstract ER -