United States. Bureau of Labor Statistics. "Manufacturing Sector - Appendix - Quarterly Data," in United States. Bureau of Labor Statistics. "Revised First-Quarter [1987] Measures for Business, Nonfarm Business, and Manufacturing and Preliminary Measures for Nonfinancial Corporations," Productivity and Costs (June 2, 1987) : 14-14. https://fraser.stlouisfed.org/title/131/item/55802/toc/452384 , accessed on May 1, 2024.