1. Compound intra-uterine and extra-uterine (lithopedion) pregnancy;Bland;Surg., Gynec. & Obst.,1933
2. A case of associated extra-uterine and intra-uterine pregnancy;Borta;Clin. ostet.,1929
3. Combined extra- and intra-uterine gestation: Case report;Brandon;Memphis M. J.,1927
4. Intra-uterine and extra-uterine bigeminal pregnancy;Crimeni;Rinascenza Medica,1932
5. Two cases of simultaneous intra-uterine and extra-uterine pregnancy with a review of recorded cases;Gemmell;J. Obst. & Gynec. Brit. Emp.,1933