RT Journal Article SR Electronic T1 Why public health is the most challenging specialty of all JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E1301 OP E1301 DO 10.1503/cmaj.171133 VO 189 IS 41 A1 Hancock, Trevor YR 2017 UL http://www.cmaj.ca/content/189/41/E1301.abstract AB