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-. "1973-1977," Annual Statistical Digest (December 1978) : 139-139. https://fraser.stlouisfed.org/title/7/item/23504/toc/110132 , accessed on April 25, 2024.