RT Journal Article SR Electronic T1 The role of medical witnesses JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 384 OP 384-b DO 10.1503/cmaj.110-2030 VO 182 IS 4 A1 H.E. Emson YR 2010 UL http://www.cmaj.ca/content/182/4/384.3.abstract