RT Journal Article SR Electronic T1 Four cases of pneumomediastinum JF Breathe JO Breathe FD European Respiratory Society SP e1 OP e6 DO 10.1183/20734735.009715 VO 11 IS 4 A1 Avinash Aujayeb A1 Jonathan Miller A1 Mark Weatherhead A1 David Cooper YR 2015 UL http://breathe.ersjournals.com/content/11/4/e1.abstract AB