共 30 条
[1]
Abma J C, 1997, Vital Health Stat 23, P1
[3]
BROOTEN D, 1994, OBSTET GYNECOL, V84, P832
[7]
DEPP R, 1991, OBSTETRICS NORMAL PR, P635
[10]
JONES RO, 1991, OBSTET GYNECOL, V77, P815