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-. "April 14, 1966," G.12.3 Industrial Production (1966-04-14) : 2-2. https://fraser.stlouisfed.org/title/55/item/59556/toc/487531 , accessed on May 2, 2024.