共 13 条
[2]
*AM COLL OBST GYN, 1995, PER INF MORT STAT
[3]
[Anonymous], 1990, WORLD HLTH STAT Q, V43, P204
[4]
DOORNBOS JP, 1987, AM J OBSTET GYNECOL, V56, P1183
[6]
GOLDENBERG RL, 1989, PUBLIC HEALTH REP, V104, P488
[8]
Joseph KS, 1996, CAN MED ASSOC J, V155, P1047
[9]
KEIRSE MJNC, 1984, LANCET, V1, P1166