U.S. Dept. of Health, Education, and Welfare, Social Security Administration, Office of Research and Statistics[1979]Staff paper
no. 32 , DHEW publication
no. (SSA) 79-11862
U.S. Dept. of Health, Education and Welfare, Social Security Administration, Office of Research and Statistics1978Staff paper
no. 30 , DHEW publication
no. (SSA) 78-11860
U.S. Dept. of Health, Education, and Welfare, Social Security Administration, Office of Research and Statistics[1978]Staff paper
no. 33 , DHEW publication
no. (SSA) 79-11863
U.S. Dept. of Health, Education, and Welfare, Social Security Administration, Office of Research and Statistics : For sale by the Supt. of Docs., U.S. G.P.O.[1977]Staff paper
no. 28 , DHEW publication
no. (SSA) 77-11853
