Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industry Groupings, Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "December 14, 1987," G.12.3 Industrial Production (1987-12-14) : 6-6. https://fraser.stlouisfed.org/title/55/item/59726/toc/474237 , accessed on May 1, 2024.