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-. "1972-1976," Annual Statistical Digest (December 1977) : 154-156. https://fraser.stlouisfed.org/title/7/item/23503/toc/117653 , accessed on May 12, 2024.