United States. Bureau of Labor Statistics. "Employees on Nonagricultural Payrolls, By Industry," in United States. Bureau of Labor Statistics. "December 1973 : Industry Statistics and Annual Review," The Employment Situation (January 11, 1974) : 17-17. https://fraser.stlouisfed.org/title/144/item/497002/toc/512268 , accessed on April 23, 2024.