http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Households and families, by type ... advance report
Volumes for 1972-1975 were classed: C 56.218:P-20/.
Advance report for: Household and family characteristics.
Current population reports. Series P-20, Population characteristics
Households, families, marital status, and living arrangements ... advance report