Fritz Heider: An Appreciation of His Book, His Influence, and His Notes by Dorwin P. Cartwright and Harold H. Kelley, Box: 39, Folder: 18. Personal papers of Fritz Heider, PP 343. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/122554 Accessed November 23, 2024.