Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industry Groupings, Not Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "April 15, 1987," G.12.3 Industrial Production (1987-04-15) : 6-6. https://fraser.stlouisfed.org/title/55/item/59718/toc/473786 , accessed on May 9, 2024.