Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Denominations in Circulation," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "May 1968," Federal Reserve Bulletin (May 1968) : 80-80. https://fraser.stlouisfed.org/title/62/item/21401/toc/241005 , accessed on April 23, 2024.