"Spherical Vibration" [typescript and drawings in looseleaf notebook], compiled by Russell Hays, February 28, 1977, Box: 9, Folder: 22. Russell Randolph Hays papers, RH MS 564. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/278255 Accessed May 06, 2024.