Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industrial Production - Indexes and Gross Value," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1992," Annual Statistical Digest (December 1993) : 113-114. https://fraser.stlouisfed.org/title/7/item/23498/toc/332869 , accessed on April 26, 2024.