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 16, 1975," G.12.3 Industrial Production (1975-06-16) : 4-4. https://fraser.stlouisfed.org/title/55/item/59597/toc/469984 , accessed on May 8, 2024.