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-. "August 15, 1972," G.12.3 Industrial Production (1972-08-15) : 8-8. https://fraser.stlouisfed.org/title/55/item/59730/toc/471359 , accessed on April 23, 2024.