United States. Bureau of Labor Statistics. "Manufacturing Sector - Appendix - Quarterly Data," in United States. Bureau of Labor Statistics. "Second Quarter 2000 [Preliminary]," Productivity and Costs (August 8, 2000) : 15-15. https://fraser.stlouisfed.org/title/131/item/55936/toc/444849 , accessed on March 28, 2024.