1. Anesthesia for preterm labor;Dailey,1987
2. Incidence and distribution of preterm labour;Hall,1985
3. Causes and prevention of preterm birth: An overview;Stubblefield,1984
4. Induction of preterm labour — why, when and how?;Macnaughton,1981
5. The fetal and neonatal effects of regional anesthesia in obstetrics;Ralston;Anesthesiology,1978