Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Mortgage Debt Outstanding," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "December 1970," Federal Reserve Bulletin (December 1970) : 152-152. https://fraser.stlouisfed.org/title/62/item/21432/toc/90768 , accessed on April 19, 2024.