1. Gallstones impacted in the stomach and duodenal bulb demonstrated by roentgenologic examination;Defeo;Am. J. Roentgenol.,1957
2. Spontaneous internal biliary fistula and gallstone obstruction, with particular reference to roentgenologic diagnosis;Borman;Surgery,1937
3. Gallstone impacted in the duodenal cap;Riesser;Radiology,1952