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. "June 1999," Federal Reserve Bulletin (June 1999) : 137-138. https://fraser.stlouisfed.org/title/62/item/20925/toc/293196 , accessed on April 25, 2024.