Pamphlet "In Memorium: A Personal Message and Gift to Your Library from Upton Sinclair,", [1961], Box: 1, Folder: 23. Upton Sinclair Literary Manuscript and Correspondence, MS 299. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/238409 Accessed December 02, 2024.