Damanti, S., F. Rosini, D. Mari, and M. Marcucci. “Facial Oedema Is Not Always Angioedema: A Case of Spontaneous Pneumomediastinum With Subcutaneous Emphysema During COPD Exacerbation”. European Journal of Case Reports in Internal Medicine, vol. 2, no. 7, Oct. 2015, doi:10.12890/2015_000281.