1. Unusual causes of spontaneous pneumoperitoneum;Madura, M.J.; Craig, R.M.; Shields, T.W.;Surg Gynecol Obstet,1982
2. Spontaneous pneumoperitoneum;Dodek, S.M.; Friedman, J.M.;Obstet Gynecol,1953
3. Misleading pneumoperitoneum;Chandler, J.G.; Berk, R.N.; Golden, G.T.;Surg Gynecol Obstet,1977
4. Gantt CB, Daniel WW, Hallenbeck GA. Nonsurgical pneumoperitoneum. Am J Surg 1977; 134: 411-4.
5. Avoiding laparotomy in nonsurgical pneumoperitoneum;Hoover, E.L.; Cole, G.D.; Mitchell, L.S.; Adams, C.Z.; Hassett, J.;Am J Surg,1992