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-. "February 15, 1977," G.12.3 Industrial Production (1977-02-15) : 3-3. https://fraser.stlouisfed.org/title/55/item/59601/toc/470159 , accessed on March 28, 2024.