Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Gross Public Debt, by Type of Security," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "May 1972," Federal Reserve Bulletin (May 1972) : 135-135. https://fraser.stlouisfed.org/title/62/item/21450/toc/56535 , accessed on April 19, 2024.