Knox, William E. (William Edward), 1901-1978. Letter to Mr. William McC. Martin, Jr., Box 14, Folder 4, William McChesney Martin, Jr., Papers. https://fraser.stlouisfed.org/content/?item_id=456807&filepath=/files/docs/historical/martin/14_04_19481201.pdf, accessed on May 22, 2018.
Regarding annual pre-Christmas luncheon with guest list
- Board of Governors of the Federal Reserve System, Federal Reserve Board
- Meltzer's History of the Federal Reserve - Primary Sources