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 15, 1964," G.12.3 Industrial Production (1964-04-15) : 2-2. https://fraser.stlouisfed.org/title/55/item/59526/toc/486186 , accessed on May 1, 2024.