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-. "June 15, 1988," G.12.3 Industrial Production (1988-06-15) : 7-7. https://fraser.stlouisfed.org/title/55/item/59736/toc/474344 , accessed on May 1, 2024.