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-. "July 14, 1971," G.12.3 Industrial Production (1971-07-14) : 2-2. https://fraser.stlouisfed.org/title/55/item/59583/toc/468218 , accessed on April 19, 2024.