Board of Governors of the Federal Reserve System (U.S.), 1935-. "Mortgage Debt Outstanding, By Type and By Type of Holder," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1972-1976," Annual Statistical Digest (December 1977) : 194-196. https://fraser.stlouisfed.org/title/7/item/23503/toc/117666 , accessed on April 17, 2024.