"Value Theory in Soviet Philosophy: A Western Confrontation", The Proceedings of the XIII International Congress of Philosophy, volume IV, pp. 133-143, 1963, Box: 13, Folder: 6. Personal papers of Richard T. De George, PP 531. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/315339 Accessed June 16, 2025.