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. "April 1986," Federal Reserve Bulletin (April 1986) : 122-123. https://fraser.stlouisfed.org/title/62/item/20767/toc/233132 , accessed on May 8, 2024.