1. Emergency surgical treatment for nonvariceal bleeding of the upper part of the gastrointestinal tract;Branicki;Surg Gynecol Obstet,1991
2. Upper gastrointestinal bleeding: Nature and magnitude of the problem in the U.S;Cutler;Dig Dis Sci,1981
3. Approach to the patient with gross gastrointestinal bleeding;Elta,1991
4. Etiology and prevalence of severe persistent upper gastrointestinal bleeding;Fleischer;Gastroenterology,1983
5. Lower gastrointestinal bleeding: The magnitude of the problem;Forde,1992