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 14, 1970," G.12.3 Industrial Production (1970-09-14) : 2-2. https://fraser.stlouisfed.org/title/55/item/59767/toc/468028 , accessed on April 18, 2024.