Study Search Results Your query returned 4 results. Series results are grouped under the most relevant study. You can ungroup series results. Results per page: 25 50 100 Sort by: Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. (?) Study Title/Investigator 1. Census of Population and Housing, 1980 [United States]: Summary Tape File 5, Special Tabulations of Population 60 Years and Over (ICPSR 8658) United States Department of Commerce. Bureau of the Census 2. County-Level Estimates of the Population Aged Sixty Years and Over by Age, Sex, and Race, 1977-1980 (ICPSR 7955) Inter-university Consortium for Political and Social Research 3. Old Age in the United States, 1880 (ICPSR 8427) Jensen, Richard; Smith, Daniel Scott; Friedberger, Mark W.; et al. 4. Old Age in the United States, 1900 (ICPSR 8428) Jensen, Richard; Smith, Daniel Scott; Friedberger, Mark W.; et al.