White Eagle - Former Chief - Horse Chief Jr. [portraits of 3 members of the Ponca tribe, from the necks up], Box: 2, Folder: 20. Osey Gail Peterson collection on Albert T. Reid, RH MS 1544. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/497060 Accessed November 23, 2024.