Board of Governors of the Federal Reserve System (U.S.), 1935-. "Federal debt subject to statutory limit-Types and ownership," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1970-1979," Annual Statistical Digest (March 1981) : 222-223. https://fraser.stlouisfed.org/title/7/item/23506/toc/190711 , accessed on April 18, 2024.