Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Indexes of Industrial Activity," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "June 1926," Federal Reserve Bulletin (June 1926) : 52-52. https://fraser.stlouisfed.org/title/62/item/20654/toc/333664 , accessed on April 25, 2024.