1. 1. Juthaba R, Jensem DM,. Acute Upper Gastrointestinal Bleeding, in: Friedman SL, Mc Quaid KR, Grendell JH (eds), Current Diagnosis & Treatment in Gastroenterology 2nd edition inc 2003; 53.
2. 2. Loren L. Gastrointestinal bleeding. In: Braunwald E, Fauci AS, Dasper DL, Hauser SL, Longo DL, Jameson JL (editors). Harrison's Principle of Internal medicine. USA: McGraw-Hill Companies Inc; 2005 : 235
3. Study design and baseline data;Silverstein;Gastrointestinal Endoscopy,1981
4. 4. Longstrenth GF: Epidemiology of hospitalization for acute upper gastrointestinal hemorrhage: A population based study. AMJ Gastroenterol 1995; 90:206.
5. 5. Jeff WJ In: Gastrointestinal Bleeding; in the Washington Manual of Medical Therapeutics University School of Medicine, St. Louis, Missouri; Lippincott. Raven Publishers, Philadelphia, and New York 1998; 302-9.