1. Combined intra and extrauterine pregnancy; a case report;ARMITAGE, G.L.; ARMITAGE, H.V.; CHESTER, P.A.;American Journal of Obstetrics and Gynaecology,1955
2. Multiple simultaneous unilateral tubal pregnancy;KAPSINOW, R.;New Orleans Medical and Surgical Journal,1951
3. Case of ruptured tubal gestation associated with twin pregnancy in uterus;MARSHALL, G.B.;Journal of Obstetrics and Gynaecology of the British Commonwealth,1903
4. Combined intrauterine and extra-uterine pregnancy; with a report of 276 cases, including two new cases observed by the author;NOVAK, E.;Surgery, Gynaecology and Obstetrics,1926
5. Ectopic pregnancy concomitant with twin intra-uterine pregnancy. A case report;PAYNE, S.; DUGE, J.; BRADBURY, W.;Obstetrics and Gynaecology,1971