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 15, 1978," G.12.3 Industrial Production (1978-12-15) : 13-13. https://fraser.stlouisfed.org/title/55/item/59783/toc/470515 , accessed on April 25, 2024.