Humphrey, Thomas M. "The Theory of Multiple Expansion Deposits : What It Is and Whence It Came," in Federal Reserve Bank of Richmond. "1986 Annual Report," Annual Report of the Federal Reserve Bank of Richmond (as of December 31, 1986) : 13-23. https://fraser.stlouisfed.org/title/471/item/18205/toc/503197 , accessed on May 8, 2024.