Letter to Marriner S. Eccles
The Marriner S. Eccles Document Collection
Includes mentioned attachment: Section 515. Joint Committee on Internal Revenue Taxation- Power to Obtain Data.
Paul, Randolph E., 1942, Letter to Marriner S. Eccles, from The Marriner S. Eccles Document Collection, accessed May 22, 2013 from FRASER, http://fraser.stlouisfed.org/docs/historical/eccles/025_13_0001.pdf