United States. Bureau of Labor Statistics. "Text," in United States. Bureau of Labor Statistics. "Third Quarter 1990 [Revised] : Business, Nonfarm Business, Manufacturing, and Nonfinancial Corporations," Productivity and Costs (December 5, 1990) : 1-5. https://fraser.stlouisfed.org/title/131/item/55974/toc/461529 , accessed on April 25, 2024.