共 14 条
[1]
ARMSTRONG RJ, 1972, STUDY INFANT MORTALI, V20
[2]
BJERKEDAL T, 1975, MED REGISTRATION BIR
[3]
CHASE HC, 1967, VITAL HLTH STATISTIC, V3
[4]
CHASE HC, 1972, VITAL HLTH STATISTIC, V20
[6]
HOFFMAN HJ, 1978, TWIN RES B
[7]
HOFFMAN HJ, UNPUB INT J GYNAECOL
[10]
MACMAHON B, 1967, VITAL HLTH STATISTIC, V22