Board of Governors of the Federal Reserve System (U.S.), 1935-. "Foreign Exchange Rates," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1980," Annual Statistical Digest (November 1981) : 169-169. https://fraser.stlouisfed.org/title/7/item/23507/toc/300839 , accessed on June 26, 2024.