PT - JOURNAL ARTICLE AU - Roger Collier TI - Drug patents: the evergreening problem AID - 10.1503/cmaj.109-4466 DP - 2013 Jun 11 TA - Canadian Medical Association Journal PG - E385--E386 VI - 185 IP - 9 4099 - http://www.cmaj.ca/content/185/9/E385.short 4100 - http://www.cmaj.ca/content/185/9/E385.full SO - CMAJ2013 Jun 11; 185