Board of Governors of the Federal Reserve System (U.S.), 1935-. "Gross public debt of the U.S. Treasury-Types and ownership," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1973-1977," Annual Statistical Digest (December 1978) : 140-142. https://fraser.stlouisfed.org/title/7/item/23504/toc/110133 , accessed on April 21, 2024.