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-. "January 14, 1971," G.12.3 Industrial Production (1971-01-14) : 4-4. https://fraser.stlouisfed.org/title/55/item/59763/toc/468180 , accessed on April 19, 2024.