Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industry Groupings, Seasonally Adjusted and Unadjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "October 18, 1971," G.12.3 Industrial Production (1971-10-18) : 3-3. https://fraser.stlouisfed.org/title/55/item/59586/toc/468239 , accessed on April 25, 2024.