http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Social-℗Ưeconomic grouping of the gainful workers of the United States, gainful workers of 1930 in social℗Ư-economic groups, by color, nativity, age, and sex, and by industry, with comparative statistics for 1920 and 1910
1 online resource (vi+264 pages), digital, PDF file
Electronic reproduction. [Bethesda, Md.] : ProQuest, 2016 digital, PDF file. ProQuest U.S. Executive Branch Documents Mode of access: World Wide Web via ProQuest website.