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-. "March 14, 1975," G.12.3 Industrial Production (1975-03-14) : 4-4. https://fraser.stlouisfed.org/title/55/item/59584/toc/469961 , accessed on May 10, 2024.