1. Obeso Carillo GA, Barge Caballero G, Canizares Carretero MA. The Earth-Heart sign: a new diagnostic finding in a patient with tension pneumomediastinum. Lancet 2014;383:486.
2. Murayama S, Gibo S. Spontaneous pneumomediastinum and Macklin effect: overview and appearance on computed tomography. World J Radiol 2014;6:850-4.
3. Macklin MT, Macklin CC. Malignant interstitial emphysema of the lungs and mediastinum as an important occult complication in many respiratory diseases and other conditions: an interpretation of the clinical literature in the light of laboratory experiment. Medicine 1944;23:281-358.