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 1980," G.12.3 Industrial Production (1981-09-01) : 4-4. https://fraser.stlouisfed.org/title/55/item/59611/toc/492563 , accessed on April 18, 2024.