1. Die Gallensteine;Wölfler,1909
2. Gallstone obstruction of the intestine;Andersen;Surg Gynecol Obstet,1967
3. Spontaneus internal biliary fistulas;Levowitz;Ann Surg,1961
4. Duodenal obstruction caused by gallstones: report of six cases;Printen;Amer Surg,1973
5. Spontaneus internal biliary fistulas;Marshall;Surg Clin N Amer,1958