1. Premature rupture of the membranes;Gibbs;Obstet Gynecol,1982
2. Causes of perinatal mortality in the U.S,. Collaborative Perinatal Project.;Naeye;JAMA,1977
3. Epidemiology of preterm delivery;Kaltreider;Clin Obstet Gynecol,1980
4. Etiology and outcome of low birth weight and preterm infants;Arias;Obstet Gynecol,1982
5. Causes and prevention of preterm birth: an overview;Stubblefield,1984