(1993). Survey of Income and Program Participation (SIPP) [1991 Panel] United States Department of Commerce. Bureau of the Census. [electronic resource].
Chicago-čujuhus (17. p.)Survey of Income and Program Participation (SIPP) [1991 Panel] United States Department of Commerce. Bureau of the Census. [electronic Resource]. 1993.
MLA-čujuhus (9. p.)Survey of Income and Program Participation (SIPP) [1991 Panel] United States Department of Commerce. Bureau of the Census. [electronic Resource]. 1993.
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