Board of Governors of the Federal Reserve System (U.S.), 1935-. "Market Yields on U.S. Government Securities at Constant Maturity," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1972-1976," Annual Statistical Digest (December 1977) : 126-128. https://fraser.stlouisfed.org/title/7/item/23503/toc/117647 , accessed on April 26, 2024.