Aiken, George D. (George David), 1892-1984. Letter to Mr. William McC. Martin, Jr., Box 11, Folder 6, William McChesney Martin, Jr., Papers. https://fraser.stlouisfed.org/scribd/?item_id=457289&filepath=/files/docs/historical/martin/11_06_19480607.pdf, accessed on November 18, 2017.
Letter from Chairman of the Senate Committee on Expenditures in the Executive Departments regarding interest paid to the Treasury Department
- Board of Governors of the Federal Reserve System, Federal Reserve Board
- Meltzer's History of the Federal Reserve - Primary Sources