共 27 条
[21]
1979, DHEW PHS801232 PUBL
[22]
1970, VITAL HLTH STATIST 2, V39
[23]
1921 36 US DEP COMM
[24]
1981, DHHS PHS821232 PUBL
[25]
1980, DHEW PHS801120 PUB S, V28
[26]
1965, VITAL HLTH STATIS 13, V6
[27]
1970 CENSUS POPULATI