The Genesis of the Earth from Scattered Sun Debris (Lecture before Houston Philosophical Society) by W.E. Pratt, 1927, Box: 4, Folder: 45. Wallace E. Pratt papers, RH MS 870. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/34055 Accessed November 28, 2024.