RT Journal Article SR Electronic T1 Dry powder inhalers are environmentally preferable to metered-dose inhalers JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E846 OP E846 DO 10.1503/cmaj.75949 VO 192 IS 29 A1 Wintemute, Kimberly A1 Miller, Fiona YR 2020 UL http://www.cmaj.ca/content/192/29/E846.abstract