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-. "September 16, 1980," G.12.3 Industrial Production (1980-09-16) : 13-13. https://fraser.stlouisfed.org/title/55/item/59636/toc/472047 , accessed on March 29, 2024.