1. Forster, A.: Die Missbidungen des Menschen. Jena, 1865.
2. Keibel, F.: Zur Entwickelungsgeschicte des menschen Urogenital-apparates. Arch, f. Anat. u. Entwcklngsgesch., Leipzig, p. 55, 1896.
3. Three demonstrations on malformations of the hind end of the body;Keith;Brit. M. J.,1908
4. Extroversion of the bladder, complicated by the presence of intestinal openings on the surface of extroverted area;Johnston;J. Anat. and Physiol.,1913
5. Etiology of exstrophy of bladder;Phillips;Arch. Surg.,1924