Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industry Groupings, Seasonally Adjusted and Unadjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "March 15, 1972," G.12.3 Industrial Production (1972-03-15) : 3-3. https://fraser.stlouisfed.org/title/55/item/59733/toc/469914 , accessed on April 19, 2024.