United States. Bureau of Labor Statistics. "Nonfinancial Corporations," in United States. Bureau of Labor Statistics. "Private Business, Nonfarm Business, and Manufacturing Sectors : Third Quarter 1980," Productivity and Costs (October 27, 1980) : 7-7. https://fraser.stlouisfed.org/title/131/item/55896/toc/437646 , accessed on April 26, 2024.