Simak - Best Sci-Fi Stories (1969), The Big Front yard (1977), Birch Clump Cylinder (1973), Catface (1979), Box: 19, Folder: 55. 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/230607 Accessed May 22, 2024.