Board of Governors of the Federal Reserve System (U.S.), 1935-. "Market Groupings, Not Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "February 16, 1971," G.12.3 Industrial Production (1971-02-16) : 4-4. https://fraser.stlouisfed.org/title/55/item/59577/toc/468186 , accessed on April 19, 2024.