Martin, William McChesney. Letter to William Gregory, Box 13, Folder 5, William McChesney Martin, Jr., Papers. https://fraser.stlouisfed.org/scribd/?item_id=456878&filepath=/files/docs/historical/martin/13_05_19460617.pdf, accessed on December 11, 2017.
Regarding Mexican financing
- Board of Governors of the Federal Reserve System, Federal Reserve Board
- Meltzer's History of the Federal Reserve - Primary Sources