1. Extra-uterine pregnancy;Schumann,1921
2. An introduction to the history of medicine;Cumston,1987
3. The changing spectrum of ectopic pregnancy;Stock;Obstet Gynecol,1988
4. Abdominal pregnancy in the United States;Atrash;Obstet Gynecol,1978
5. Abdominal pregnancy;Delke;Obstet Gynecol,1982