1. Subcutaneous emphysema following rectal perforation;Borgström;Acta Chirurgica Scandinavica,1953
2. Retroperitoneal rupture of the duodenum due to blunt non-penetrating abdominal trauma;Gould;Radiology,1963
3. Retroperitoneal pneumography: safe method using carbon dioxide;McLelland;Radiological Clinics of North America,1969
4. Combined occurrence of retropneumoperitoneum and pneumoperitoneum;Calenoff;American Journal of Roentgenography Radium Therapy and Nuclear Medicine,1973
5. Pneumatosis intestinalis: new concept;Keyting;Radiology,1961