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-. "May 13, 1991," G.17 Industrial Production and Capacity Utilization (1991-05-13) : 6-7. https://fraser.stlouisfed.org/title/77/item/63590/toc/454811 , accessed on April 25, 2024.