共 8 条
[1]
ELSTER AD, 1991, OBSTET GYNECOL, V77, P387
[4]
TRIPLETS AND HIGHER-ORDER MULTIPLE BIRTHS - TIME TRENDS AND INFANT-MORTALITY
[J].
AMERICAN JOURNAL OF DISEASES OF CHILDREN,
1992, 146 (07)
:862-868
[7]
SHOLL J, 1994, AM J OBSTET GYNECOL, V170, P338
[8]
1993, VITAL STATISTICS US