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, 1988," G.12.3 Industrial Production (1988-04-15) : 7-7. https://fraser.stlouisfed.org/title/55/item/59776/toc/474312 , accessed on March 28, 2024.