United States. Bureau of Labor Statistics. "Employed and Unemployed Persons by Occupation, Not Seasonally Adjusted," in United States. Bureau of Labor Statistics. "December 2005," The Employment Situation (January 6, 2006) : 17-17. https://fraser.stlouisfed.org/title/144/item/494785/toc/508750 , accessed on May 3, 2024.