Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industrial Production: Industry Groups," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "July 15, 1991," G.17 Industrial Production and Capacity Utilization (1991-07-15) : 6-7. https://fraser.stlouisfed.org/title/77/item/63592/toc/454837 , accessed on May 3, 2024.