RT Journal Article SR Electronic T1 Joseph Arthur MacFarlane JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1067 OP 1070 VO 94 IS 20 A1 MacDonald, R. I. A1 Hamilton, J. A1 Porter, D. A1 Kelly, A. D. YR 1966 UL http://www.cmaj.ca/content/94/20/1067.abstract