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-. "July 17, 1972," G.12.3 Industrial Production (1972-07-17) : 8-8. https://fraser.stlouisfed.org/title/55/item/59728/toc/471347 , accessed on May 7, 2024.