United States. Bureau of Labor Statistics. "Manufacturing Sector," in United States. Bureau of Labor Statistics. "Private Business, Nonfarm Business, and Manufacturing Sectors : Third Quarter 1981," Productivity and Costs (October 29, 1981) : 8-8. https://fraser.stlouisfed.org/title/131/item/55904/toc/486644 , accessed on April 25, 2024.