United States. President and Council of Economic Advisers (U.S.). "U.S. Treasury Securities Outstanding by Kind of Obligation," in United States. President and Council of Economic Advisers (U.S.). "2017," Economic Report of the President (2017) : 595-595. https://fraser.stlouisfed.org/title/45/item/535300/toc/519051 , accessed on April 24, 2024.