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-. "September 14, 1979," G.12.3 Industrial Production (1979-09-14) : 14-14. https://fraser.stlouisfed.org/title/55/item/59622/toc/470677 , accessed on May 2, 2024.