1. Vaginal birth after cesarean;Phelan;Am J Obstet Gynecol,1987
2. Vaginal delivery after cesarean section in women with unknown types of uterine scar;Beall;J Reprod Med,1984
3. Vaginal delivery in patients with a prior cesarean section;Lavin;Obstet Gynecol,1982
4. Multiple gestation;Benirschke,1984
5. Vaginal delivery of twins after previous cesarean section;Brady;N Engl J Med,1988