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-. "December 14, 1979," G.12.3 Industrial Production (1979-12-14) : 13-13. https://fraser.stlouisfed.org/title/55/item/59627/toc/470730 , accessed on March 29, 2024.