共 16 条
[1]
BAKKETEIG LS, 1978, ACTA OBSTET GYNECO S, V77, P1
[3]
Friedman Aryeh S., 1986, COLUM BUS L REV, P1
[6]
HOBEL CJ, 1973, AM J OBSTET GYNECOL, V117, P1
[7]
KLEINBAUM DG, 1982, EPIDEMIOLOGIC RES
[9]
MCCORMICK MC, 1985, JAMA-J AM MED ASSOC, V253, P799