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-. "October 17, 1972," G.12.3 Industrial Production (1972-10-17) : 8-8. https://fraser.stlouisfed.org/title/55/item/59703/toc/471373 , accessed on April 18, 2024.