Description of Major Industry Groups
United States. Bureau of Employment Security. "Description of Major Industry Groups," in United States. Bureau of Employment Security. "Employment Security Memorandum, No. 17," Employment and Pay Rolls in State Unemployment Compensation Systems, 1938 (1939) : 50-67. https://fraser.stlouisfed.org/title/193/item/5443/toc/208017 , accessed on May 10, 2024.