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-. "October 16, 1969," G.12.3 Industrial Production (1969-10-16) : 2-2. https://fraser.stlouisfed.org/title/55/item/59555/toc/492496 , accessed on April 19, 2024.