1. Roth JLA, Stein GN, Morrissey JF, Stein EJ: Diagnosis of peptic ulcer.In Bockus Gastroenterology. JE Berk, WS Haubrich, MH Kalser, JLA Roth, F Schaffner (eds). Philadelphia, WB Saunders, 1985, p 1082
2. Hauser G: Die Krebsige Entartung des chronischen Magenund Duodenalgeschwures.In Handbuch der speziellen pathologischen Anatomie und Histologie. F Henke, O Lubarsch (eds). Berlin, Springer, 1926, pp 497?518
3. Newcomb WD: The relationship between peptic ulceration and gastric carcinoma. Br J Surg 20:279?308, 1932
4. Ewing J: The beginnings of gastric cancer. Am J Surg 31:204?206, 1936
5. Palmer WL, Humphreys EM: Gastric carcinoma: Observations on peptic ulceration and healing. Gastroenterology 3:257?274, 1944