TY - JOUR T1 - The study of NOELs JF - Canadian Medical Association Journal JO - CMAJ SP - 1539 LP - 1539 DO - 10.1503/cmaj.1041767 VL - 172 IS - 12 AU - John C. Clifford Y1 - 2005/06/07 UR - http://www.cmaj.ca/content/172/12/1539.1.abstract ER -