Board of Governors of the Federal Reserve System (U.S.), 1935-. "Summary Groupings, Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "June 14, 1974," G.12.3 Industrial Production (1974-06-14) : 8-8. https://fraser.stlouisfed.org/title/55/item/59803/toc/471529 , accessed on April 25, 2024.