CULVER, G J Benign ulcer of the fourth portion of the duodenum. [electronic resource] - The American journal of roentgenology and radium therapy Mar 1947 - 333-7 p. digital Publication Type: Journal Article ISSN: 0092-5632 Subjects--Topical Terms: DuodenumHumansPeptic Ulcer--diagnostic imagingRadiographyUlcer