Author,Title,Edition,Publisher,Year,Series,Number,ISBN,ISSN,URL
"Edwards, Alba M. and United States. Bureau of the Census","A social-economic grouping of the gainful workers of the United States, 1930 : with appendix",,Ross Pub.,2003,Census of the United States,,0883545667,,https://cir.nii.ac.jp/crid/1130000798088266112