Nachlass: Groener, Nummer: N/46, Archiv: Militaerarchiv, Ort: Freiburg, Teilnummer: 162, Box: 4, Folder: 56-57. German State Documents, RH MS 228. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/6655 Accessed April 28, 2025.