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-. "July 15, 1988," G.12.3 Industrial Production (1988-07-15) : 6-6. https://fraser.stlouisfed.org/title/55/item/59737/toc/474361 , accessed on June 28, 2024.