RT Journal Article SR Electronic T1 Is informed consent in research sometimes optional? JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 495 OP 495 DO 10.1503/cmaj.109-4753 VO 186 IS 7 A1 Shuchman, Miriam YR 2014 UL http://www.cmaj.ca/content/186/7/495.abstract AB