1. The “ring around the artery” sign in pneumomediastinum;Hammond;J Can Assoc Radiol,1984
2. Another look at the “ring around the artery” in pneumomediastinum;Landay;J Can Assoc Radiol,1985
3. Recurrent idiopathic pneumomediastinum;Channer;Postgrad Med,1985
4. Subcutaneous and mediastinal emphysema: pathophysiology, diagnosis, and management;Maunder;Arch Intern Med,1984
5. Pneumothorax, pneumomediastinum, and pneumopericardium following Valsalva's maneuver during marijuana smoking;Birrer;NY State J Med,1984