United States. Bureau of Labor Statistics. "Nonfarm Business Sector - Appendix - Quarterly Data," in United States. Bureau of Labor Statistics. "Second Quarter 2000 [Preliminary]," Productivity and Costs (August 8, 2000) : 14-14. https://fraser.stlouisfed.org/title/131/item/55936/toc/444848 , accessed on April 27, 2024.