1. Synchronous upper and lower gastrointestinal endoscopy is an effective method of investigating iron-deficiency anaemia;Hardwick;Br J Surg,1998
2. The role of endoscopy in the evaluation of iron deficiency anemia in patients over the age of 50;Gordon;Am J Gastroenterol,1994
3. Relative frequency of upper gastrointestinal and colonic lesions in patients with positive fecal occult-blood tests;Rockey;N Engl J Med,1998
4. Is there a role for upper gastrointestinal endoscopy in the evaluation of patients with occult blood-positive stool and negative colonoscopy?;Chen;Am J Gastroenterol,1993
5. Yield of dual endoscopy for positive fecal occult blood test;Ali;Am J Gastroenterol,2003