References
- Berven, E. (1930)Munchen
- Berven, E.
- Rohdenburg and Prime (1921) Arch. of surg., p. 116.
- Westermark (1927) Skand. Arch. f. Phys.
- Stephan (1912) Beitr. z. klin. Chir., p. 382.
- Clark, Morgan and Asnis (1924) Radiology, p. 233.
- Posener Virch. Arch., p. 79.