Board of Governors of the Federal Reserve System (U.S.), 1935-. "Notes to Tables," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1987," Annual Statistical Digest (October 1988) : 241-256. https://fraser.stlouisfed.org/title/7/item/23493/toc/193510 , accessed on March 28, 2024.