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-. "July 15, 1977," G.12.3 Industrial Production (1977-07-15) : 4-4. https://fraser.stlouisfed.org/title/55/item/59787/toc/470218 , accessed on April 30, 2024.