United States. Bureau of Labor Statistics. "Footnotes," in United States. Bureau of Labor Statistics. "Private Business, Nonfarm Business, and Manufacturing Sectors : Third Quarter 1976," Productivity and Costs (October 27, 1976) : 13-13. https://fraser.stlouisfed.org/title/131/item/55871/toc/433582 , accessed on April 23, 2024.