Board of Governors of the Federal Reserve System (U.S.), 1935-. "Market Groupings, Not Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "December 16, 1980," G.12.3 Industrial Production (1980-12-16) : 4-4. https://fraser.stlouisfed.org/title/55/item/59639/toc/472104 , accessed on April 25, 2024.