Board of Governors of the Federal Reserve System (U.S.), 1935-. "Market Groupings, Not Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1987 Revision," G.12.3 Industrial Production (1987-01-01) : 13-14. https://fraser.stlouisfed.org/title/55/item/59714/toc/492574 , accessed on April 25, 2024.