共 8 条
[1]
BARSS VA, 1985, OBSTET GYNECOL, V66, P779
[3]
HANNA JH, 1984, OBSTET GYNECOL, V63, P126
[6]
NYBERG DA, 1984, J ULTRAS MED, V3, P29
[7]
PRITCHARD JA, 1985, WILLIAMS OBSTETRICS, P503