Board of Governors of the Federal Reserve System (U.S.), 1935-. "Diffusion Indexes," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "January 18, 1989," G.12.3 Industrial Production (1989-01-18) : 15-15. https://fraser.stlouisfed.org/title/55/item/59744/toc/474465 , accessed on April 25, 2024.