Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Industrial Production - Indexes and Gross Value," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "July 1981," Federal Reserve Bulletin (July 1981) : 112-113. https://fraser.stlouisfed.org/title/62/item/20479/toc/44245 , accessed on May 7, 2024.