APA

Copper R. L., Goldenberg R. L., Das A., Elder N., Swain M., Norman G., Ramsey R., Cotroneo P., Collins B. A., Johnson F., Jones P. & Meier A. M. (19970102). The preterm prediction study: maternal stress is associated with spontaneous preterm birth at less than thirty-five weeks' gestation. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. : American journal of obstetrics and gynecology.

Chicago

Copper R L, Goldenberg R L, Das A, Elder N, Swain M, Norman G, Ramsey R, Cotroneo P, Collins B A, Johnson F, Jones P and Meier A M. 19970102. The preterm prediction study: maternal stress is associated with spontaneous preterm birth at less than thirty-five weeks' gestation. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. : American journal of obstetrics and gynecology.

Harvard

Copper R. L., Goldenberg R. L., Das A., Elder N., Swain M., Norman G., Ramsey R., Cotroneo P., Collins B. A., Johnson F., Jones P. and Meier A. M. (19970102). The preterm prediction study: maternal stress is associated with spontaneous preterm birth at less than thirty-five weeks' gestation. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. : American journal of obstetrics and gynecology.

MLA

Copper R L, Goldenberg R L, Das A, Elder N, Swain M, Norman G, Ramsey R, Cotroneo P, Collins B A, Johnson F, Jones P and Meier A M. The preterm prediction study: maternal stress is associated with spontaneous preterm birth at less than thirty-five weeks' gestation. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. : American journal of obstetrics and gynecology. 19970102.