BRIEF [O.A.] Schlichting, Marie Author: Schlichting, Marie Recipient: Haeckel, Ernst Dating: 20.11.1918
BRIEF [O.A.] Klotz, Karl Author: Klotz, Karl Recipient: Haeckel, Ernst Corporation: Karl Klotz, Reform-Versandhaus Dating: 02.09.1914
BRIEF [O.A.] Kistowski, Werner von Author: Kistowski, Werner von Recipient: Haeckel, Ernst Dating: 14.02.1917
BRIEF [O.A.] Schröter, Wilhelm Author: Schröter, Wilhelm Recipient: Haeckel, Ernst Corporation: Maler & Lithograph für Naturwissenschaften Dating: 21.11.1914
BRIEF [O.A.] Schröter, Wilhelm Author: Schröter, Wilhelm Recipient: Haeckel, Ernst Corporation: Maler & Lithograph für Naturwissenschaften Dating: 14.12.1914
BRIEF [O.A.] Leuchtenberg, Anna Author: Leuchtenberg, Anna Recipient: Haeckel, Ernst Dating: 14.02.1911