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-. "Industrial Production Indexes 1976," G.12.3 Industrial Production (1977-09-01) : 4-4. https://fraser.stlouisfed.org/title/55/item/59789/toc/492484 , accessed on May 2, 2024.