Maffry, August, 1905-. Letter to Raymond W. Duning, Box 13, Folder 6, William McChesney Martin, Jr., Papers. https://fraser.stlouisfed.org/scribd/?item_id=456879&filepath=/files/docs/historical/martin/13_06_19461231.pdf, accessed on December 11, 2017.
Transmitting article by Martin "Foreign Trade Financing Through the Export-Import Bank."
- Board of Governors of the Federal Reserve System, Federal Reserve Board
- Meltzer's History of the Federal Reserve - Primary Sources