1. Way LW: Abdominal pain.In Gastrointestinal Disease, M Sleisenger, J Fordtran (eds). Philadelphia, W.B. Saunders, 1983, pp 207?221
2. Soll AH, Isenberg JI: Duodenal ulcer diseases.In Gastrointestinal Disease, M Sleisenger J Fordtran (eds). Philadelphia, W.B. Saunders, 1983, pp 625?672
3. Müller-Lissner, SA: Symptomatik des peptischen Ulcus.In Ulcustherapie, AL Blum, JR Siewert (eds). Berlin, Heidelberg, New York, Springer-Verlag, 1982, pp 113?122
4. Sheppard MC, Holmes GKT, Cockel R: Clinical picture of peptic ulceration diagnosed endoscopically. Gut 18:524?530, 1977
5. Moynihan BGA: Duodenal ulcer. Philadelphia-London, WB Saunders, 1910, pp 101?121