共 48 条
[2]
BABAKNIA A, 1977, OBSTET GYNECOL, V50, P40
[3]
BECK WW, 1974, OBSTET GYNECOL, V43, P374
[4]
Becker W F, 1976, J La State Med Soc, V128, P221
[5]
BONICA JJ, 1969, PRINCIPLES PRACTICE, V2, P1379
[7]
BURGESS GE, 1979, OBSTET GYNECOL, V53, P266
[8]
BURROW GN, 1978, NEW ENGL J MED, V298, P150