United States. Bureau of Labor Statistics. "Business Sector - Appendix - Quarterly Data," in United States. Bureau of Labor Statistics. "First Quarter 1995 [Revised]," Productivity and Costs (June 21, 1995) : 16-16. https://fraser.stlouisfed.org/title/131/item/55919/toc/488626 , accessed on April 23, 2024.