RT Journal Article SR Electronic T1 Spontaneous pneumomediastinum JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E276 OP E276 DO 10.1503/cmaj.081661 VO 181 IS 12 A1 Emmet E. McGrath A1 Zoe Blades A1 Chris Barber YR 2009 UL http://www.cmaj.ca/content/181/12/E276.abstract