United States. Bureau of Labor Statistics. "Footnotes," in United States. Bureau of Labor Statistics. "Productivity and Costs in Nonfinancial Corporations (and Revised Figures for the Private Economy) : Third Quarter 1973," Productivity and Costs (November 27, 1973) : 9-9. https://fraser.stlouisfed.org/title/131/item/55986/toc/494619 , accessed on April 25, 2024.