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 17, 1972," G.12.3 Industrial Production (1972-01-17) : 8-8. https://fraser.stlouisfed.org/title/55/item/59791/toc/450947 , accessed on May 11, 2024.