Board of Governors of the Federal Reserve System (U.S.), 1935-. "Market Groupings, Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industrial Production Indexes 1979," G.12.3 Industrial Production (1980-09-01) : 2-2. https://fraser.stlouisfed.org/title/55/item/59635/toc/492550 , accessed on April 28, 2024.