United States. Bureau of Labor Statistics. "Nondurable Manufacturing Sector - Appendix - Quarterly Data," in United States. Bureau of Labor Statistics. "Private Business, Nonfarm Business, and Manufacturing Sectors : Fourth Quarter 1980 and Annual Averages for 1980," Productivity and Costs (January 30, 1981) : 20-20. https://fraser.stlouisfed.org/title/131/item/55899/toc/437737 , accessed on March 28, 2024.