共 4 条
- [1] Timor-Tritsch I.E., Rottem S., Elgali S., Transvaginal Sonography, (1987)
- [2] Cyr D.R., Mach L.A., Nyberg D.A., Et al., Fetal rhombencephalon: Normal ultrasound finding, Radiology, 166, (1988)
- [3] Green J.J., Hobbins J.C., Abdominal ultrasound examination of the first trimester fetus, Am J Obstet Gynecol, 159, (1988)
- [4] Official guidelines and statements on obstetrical ultrasound, (1983)