RT Journal Article SR Electronic T1 A quartet of intruders JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E42 OP E43 DO 10.1503/cmaj.190802 VO 192 IS 2 A1 Oloruntoba, Tolu YR 2020 UL http://www.cmaj.ca/content/192/2/E42.abstract