Evanoff, Douglas Darrell, 1951- and Israilevich, Philip R. "Productive Efficiency in Banking," in Federal Reserve Bank of Chicago. "July/August 1991, Volume XV, Issue 4," Economic Perspectives (Federal Reserve Bank of Chicago) (July/August 1991) : 12-29. https://fraser.stlouisfed.org/title/5288/item/552480/toc/521925 , accessed on April 18, 2024.