United States. Bureau of Labor Statistics. "Productivity Measures for Selected Industries," in United States. Bureau of Labor Statistics. "Private Business, Nonfarm Business, and Manufacturing Sectors : First Quarter 1982," Productivity and Costs (April 29, 1982) : 3-3. https://fraser.stlouisfed.org/title/131/item/55998/toc/486681 , accessed on April 25, 2024.