TY - JOUR T1 - Crackdown on factory farm drug use urged JF - Canadian Medical Association Journal JO - CMAJ SP - E23 LP - E24 DO - 10.1503/cmaj.109-4055 VL - 184 IS - 1 AU - Paul Christopher Webster Y1 - 2012/01/10 UR - http://www.cmaj.ca/content/184/1/E23.abstract ER -