共 45 条
[41]
*US BUR CENS, 1955, PE2A SPEC REP, P174
[42]
*US BUR CENS, 1943, POP FAM TYP FAM 1940, P24
[43]
*US STAT SOC SEC B, 1942, 45 BUR MEM, V6, P3
[45]
WITTMAN MP, 1945, J GENET PSYCHOL, V66, P167