The New Knowledge: A Simple Exposition of the New Physics and the New Chemistry in Their Relation to the New Theory of Matter by Robert Kennedy Duncan [with inscription to E.H.S. Bailey by the author, Sept 30, 1907], 1906, Box: 6, Volume: 92. Personal papers of E.H.S. Bailey, PP 158. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/116443 Accessed October 31, 2024.