ROMERO, R, GOMEZ, R, SEPULVEDA, W. (1992). THE UTERINE CERVIX, ULTRASOUND AND PREMATURITY
.
ULTRASOUND IN OBSTETRICS & GYNECOLOGY, 2(6), 385-388. 10.1046/j.1469-0705.1992.02060384-2.x
ROMERO, R, GOMEZ, R, SEPULVEDA, W. (1992). THE UTERINE CERVIX, ULTRASOUND AND PREMATURITY
. ULTRASOUND IN OBSTETRICS & GYNECOLOGY, 2(6), 385-388. 10.1046/j.1469-0705.1992.02060384-2.x