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-. "March 26, 1976," G.12.3 Industrial Production (1976-03-26) : 4-4. https://fraser.stlouisfed.org/title/55/item/59530/toc/470047 , accessed on May 9, 2024.