United States. Bureau of Labor Statistics. "Unemployed Persons by Industry and Class of Worker, Not Seasonally Adjusted," in United States. Bureau of Labor Statistics. "December 2008," The Employment Situation (January 9, 2009) : 21-21. https://fraser.stlouisfed.org/title/144/item/494821/toc/507938 , accessed on April 28, 2024.