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-. "June 14, 1974," G.12.3 Industrial Production (1974-06-14) : 4-4. https://fraser.stlouisfed.org/title/55/item/59803/toc/471531 , accessed on May 4, 2024.