RT Journal Article SR Electronic T1 Grading evidence JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 929 OP 930 DO 10.1503/cmaj.1040014 VO 170 IS 6 A1 Schünemann, Holger J. A1 Best, Dana A1 Vist, Gunn A1 Oxman, Andrew D. YR 2004 UL http://www.cmaj.ca/content/170/6/929.abstract