TY - JOUR T1 - Cause and effect JF - Canadian Medical Association Journal JO - CMAJ SP - 312 LP - 313 VL - 160 IS - 3 AU - M. A. Baltzan Y1 - 1999/02/09 UR - http://www.cmaj.ca/content/160/3/312.3.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -