RT Journal Article SR Electronic T1 Opioids and chronic pain JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 73 OP 73 DO 10.1503/cmaj.112-2001 VO 184 IS 1 A1 Lisa Bromley YR 2012 UL http://www.cmaj.ca/content/184/1/73.1.abstract