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 : First Quarter 1979," Productivity and Costs (May 29, 1979) : 16-16. https://fraser.stlouisfed.org/title/131/item/55886/toc/495061 , accessed on March 29, 2024.