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-. "June 14, 1991," G.17 Industrial Production and Capacity Utilization (1991-06-14) : 6-7. https://fraser.stlouisfed.org/title/77/item/63591/toc/454827 , accessed on May 4, 2024.