1. Ectopic pregnancy surveillance, United States, 1970–1987;MMWR,1988
2. National trends in the management of tubal pregnancy. 1970–1987;Young;Obstet Gynecol,1991
3. Ectopic pregnancy mortality in the United States, 1970–1983;Atrash;Obstet Gynecol,1987
4. Center for Disease Control: Ectopic pregnancy in the United States: 1981–1983;MMWR,1986