Arnold, Henry Harley, 1886-1950. Letter to Brig. General O.W. Griswold, Box 9, Folder 5, William McChesney Martin, Jr., Papers. https://fraser.stlouisfed.org/content/?item_id=457113&filepath=/files/docs/historical/martin/09_05_19410725.pdf, accessed on May 23, 2018.
- Board of Governors of the Federal Reserve System, Federal Reserve Board
- Meltzer's History of the Federal Reserve - Primary Sources