共 25 条
[1]
[Anonymous], 2007, NATL VITAL STAT REP
[2]
BARCLAY DL, 1970, OBSTET GYNECOL, V35, P120
[3]
CHESTNUT DH, 1985, OBSTET GYNECOL, V65, P365
[4]
Eniola O A, 2006, J Obstet Gynaecol, V26, P104, DOI 10.1080/01443610500443196