1. Long term results of medical and surgical treatment of peptic ulcer;Krause;Acta Chir Scand,1963
2. Long-term prognosis in medically treated peptic ulcer;Krag;Acta Med Scand,1966
3. Incidence of natural history of gastric and duodenal ulcer;Pulvertaft;Postgrad Med J,1968
4. A comparison of the course of the disease among patients with gastric ulcer, duodenal ulcer, and ulcer dyspepsia without ulcer demonstrable by X-ray;Viskum;Dan Med Bull,1976
5. Peptic ulcer: a profile;Fry;Br Med J,1964