Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "U.S. Government Marketable and Convertible Securities Outstanding," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "March 1968," Federal Reserve Bulletin (March 1968) : 134-134. https://fraser.stlouisfed.org/title/62/item/21399/toc/5610 , accessed on April 18, 2024.