Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industry Groupings, Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "December 15, 1970," G.12.3 Industrial Production (1970-12-15) : 3-3. https://fraser.stlouisfed.org/title/55/item/59764/toc/468171 , accessed on April 23, 2024.