United States. Bureau of Labor Statistics. "Unit Costs, Unit Profits and Prices In Nonfinancial Corporations," in United States. Bureau of Labor Statistics. "Nonfinancial Corporate Sector : Third Quarter 1979," Productivity and Costs (November 28, 1979) : 14-14. https://fraser.stlouisfed.org/title/131/item/55892/toc/495098 , accessed on April 23, 2024.