POSTKARTE Kellermann, Carl Alfred Author: Kellermann, Carl Alfred Recipient: Haeckel, Ernst Dating: 14.03.1906
BRIEF [O.A.] Kiepenheuer, Gustav Author: Kiepenheuer, Gustav Recipient: Haeckel, Ernst Corporation: Gustav Kiepenheuer Verlag in Weimar Dating: 14.09.1914
BRIEF OHNE UMSCHLAG Steman, Friedrich Author: Steman, Friedrich Recipient: Haeckel, Ernst Dating: 08.02.1900
BRIEF OHNE UMSCHLAG Dittmar, Karl Author: Dittmar, Karl Recipient: Haeckel, Ernst Corporation: Herzogtum Sachsen Dating: 10.11.1913
BRIEF [O.A.] Knobloch, Henriette von Author: Knobloch, Henriette von Recipient: Haeckel, Ernst Dating: 08.10.1913
BRIEF [O.A.] Bojanowski, Paul von Author: Bojanowski, Paul von Recipient: Haeckel, Ernst Dating: 11.12.1914
TELEGRAMM Sachsen-Meiningen, Feodora Karola Charlotte Marie Adelheid Auguste Mathilde von Author: Sachsen-Meiningen, Feodora Karola Charlotte Marie Adelheid Auguste Mathilde von Recipient: Haeckel, Ernst Dating: 09.03.1917
