@misc{misc7c558bf3, title = {Cervical lenght distribution in early pregnancy by transvaginal ultrasonography}, author = {Carvalho, M H B and Brizot, Maria L and Bittar, Roberto Eduardo and Miyadahira, Seizo and Zugaib, Marcelo}, year = {1998}, booktitle = {World Congress on Ultrasound in Obstetrics and Gynecology} }