This primary source comes from the Collection HH-HOOVH: Herbert Hoover Papers.
Full Citation: Letter from Attorney General William Mitchell to President Herbert Hoover; 11/21/1931; Unemployment-POUR-Correspondence, Nov 16-30, 1931; President's Subject Files, 1929 - 1935; Collection HH-HOOVH: Herbert Hoover Papers; Herbert Hoover Library, West Branch, IA. [Online Version, https://www.docsteach.org/documents/document/letter-from-attorney-general-william-mitchell-to-president-herbert-hoover, May 3, 2024]