Sixteenth Census of the United States: 1940: A Comparison of the 1930 and the 1940 Census Occupation and Industry Classifications and Statistics ; a Comparable Series of Occupation Statistics, 1870 to 1930 ; and a Social-economic Grouping of the Labor Force, 1910 to 1940. Population. Comparative occupation statistics for the United States, 1870 to 1940
Alba M. Edwards · United States. Bureau of the Census
Jan 1943 · U.S. Government Printing Office