Board of Governors of the Federal Reserve System (U.S.), 1935-. "Market Groupings, Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "September 16, 1980," G.12.3 Industrial Production (1980-09-16) : 3-3. https://fraser.stlouisfed.org/title/55/item/59636/toc/472041 , accessed on April 18, 2024.