APA

Okun N., Summers A. M., Hoffman B., Huang T., Winsor E., Chitayat D., Staines A. & Johnson J. (20090319). Prospective experience with integrated prenatal screening and first trimester combined screening for trisomy 21 in a large Canadian urban center. : Prenatal diagnosis.

Chicago

Okun Nanette, Summers Anne M, Hoffman Barry, Huang Tianhua, Winsor Elizabeth, Chitayat David, Staines A and Johnson Jo-Ann. 20090319. Prospective experience with integrated prenatal screening and first trimester combined screening for trisomy 21 in a large Canadian urban center. : Prenatal diagnosis.

Harvard

Okun N., Summers A. M., Hoffman B., Huang T., Winsor E., Chitayat D., Staines A. and Johnson J. (20090319). Prospective experience with integrated prenatal screening and first trimester combined screening for trisomy 21 in a large Canadian urban center. : Prenatal diagnosis.

MLA

Okun Nanette, Summers Anne M, Hoffman Barry, Huang Tianhua, Winsor Elizabeth, Chitayat David, Staines A and Johnson Jo-Ann. Prospective experience with integrated prenatal screening and first trimester combined screening for trisomy 21 in a large Canadian urban center. : Prenatal diagnosis. 20090319.