APA

Yaron Y., Cherry M., Kramer R. L., O'Brien J. E., Hallak M., Johnson M. P. & Evans M. I. (19991118). Second-trimester maternal serum marker screening: maternal serum alpha-fetoprotein, beta-human chorionic gonadotropin, estriol, and their various combinations as predictors of pregnancy outcome. : American journal of obstetrics and gynecology.

Chicago

Yaron Y, Cherry M, Kramer R L, O'Brien J E, Hallak M, Johnson M P and Evans M I. 19991118. Second-trimester maternal serum marker screening: maternal serum alpha-fetoprotein, beta-human chorionic gonadotropin, estriol, and their various combinations as predictors of pregnancy outcome. : American journal of obstetrics and gynecology.

Harvard

Yaron Y., Cherry M., Kramer R. L., O'Brien J. E., Hallak M., Johnson M. P. and Evans M. I. (19991118). Second-trimester maternal serum marker screening: maternal serum alpha-fetoprotein, beta-human chorionic gonadotropin, estriol, and their various combinations as predictors of pregnancy outcome. : American journal of obstetrics and gynecology.

MLA

Yaron Y, Cherry M, Kramer R L, O'Brien J E, Hallak M, Johnson M P and Evans M I. Second-trimester maternal serum marker screening: maternal serum alpha-fetoprotein, beta-human chorionic gonadotropin, estriol, and their various combinations as predictors of pregnancy outcome. : American journal of obstetrics and gynecology. 19991118.