RT Journal Article SR Electronic T1 US calls for more restrictions on e-cigarettes for youth JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E131 OP E131 DO 10.1503/cmaj.109-5374 VO 189 IS 3 A1 Rankin, Jay YR 2017 UL http://www.cmaj.ca/content/189/3/E131.abstract