Board of Governors of the Federal Reserve System (U.S.), 1935-. "Symbols and Abbreviations," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1990-1995," Annual Statistical Digest (November 1996) : 4-4. https://fraser.stlouisfed.org/title/7/item/23501/toc/204578 , accessed on April 23, 2024.