United States. Bureau of Labor Statistics. "Footnotes," in United States. Bureau of Labor Statistics. "Private Business, Nonfarm Business, and Manufacturing Sectors : First Quarter 1979 (and Data for Nonfinancial Corporations, Fourth Quarter 1978)," Productivity and Costs (April 30, 1979) : 12-12. https://fraser.stlouisfed.org/title/131/item/55976/toc/495082 , accessed on May 1, 2024.