Board of Governors of the Federal Reserve System (U.S.), 1935-. "Margin Requirements," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1972-1976," Annual Statistical Digest (December 1977) : 51-51. https://fraser.stlouisfed.org/title/7/item/23503/toc/117629 , accessed on April 23, 2024.