Cervical Sonography in Preterm LaborJay D. Iams, Francee Johnson, MB Landon et al.|Journal of diagnostic medical sonography|1994Cited by 195
Measurement of cervical length in pregnancy: comparison between vaginal ultrasonography and digital examination.Jiri Sonek, Steven G. Gabbe, Jay D. Iams et al.|PubMed|1990Cited by 151