Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Kinds of United States Currency Outstanding and in Circulation," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "May 1956," Federal Reserve Bulletin (May 1956) : 40-40. https://fraser.stlouisfed.org/title/62/item/21257/toc/287886 , accessed on April 19, 2024.