United States. Bureau of Labor Statistics. "Nondurable Manufacturing Sector - Appendix - Quarterly Data," in United States. Bureau of Labor Statistics. "Second Quarter 1997 [Preliminary]," Productivity and Costs (August 12, 1997) : 17-17. https://fraser.stlouisfed.org/title/131/item/55927/toc/433755 , accessed on April 26, 2024.