Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Number in Operation," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "April 1972," Federal Reserve Bulletin (April 1972) : 210-211. https://fraser.stlouisfed.org/title/62/item/21448/toc/358437 , accessed on April 27, 2024.