Edmondson - The Last Stage to Opal (1977), The Last Stage from Opal (1979), The Long Trail North (1974, 1977), Box: 6, Folder: 5. Corporate Papers of the Robert Mills Literary Agency, MS 307. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/230148 Accessed May 02, 2024.