1. The ecology of medical care;White;N Engl J Med,1961
2. Sample selection and the natural history of disease: studies of febrile seizures;Ellenberg;JAMA,1980
3. Fractures of the pelvis: trauma mechanism, types of injury and principles of treatment;Huittinen;Acta Chir Scand,1972
4. Laparotomy for pelvic fracture;Zannis;Am J Surg,1980
5. Epidemiologic features of pelvic fractures;Melton;Clin Orthop,1981