United States. Bureau of Labor Statistics. "Employed and Unemployed Persons by Occupation, Not Seasonally Adjusted," in United States. Bureau of Labor Statistics. "May 2003," The Employment Situation (June 6, 2003) : 17-17. https://fraser.stlouisfed.org/title/144/item/494754/toc/509432 , accessed on April 17, 2024.