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-. "January 15, 1975," G.12.3 Industrial Production (1975-01-15) : 8-8. https://fraser.stlouisfed.org/title/55/item/59802/toc/469930 , accessed on May 2, 2024.