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-. "December 14, 1966," G.12.3 Industrial Production (1966-12-14) : 4-4. https://fraser.stlouisfed.org/title/55/item/59805/toc/487858 , accessed on May 4, 2024.