BRIEF OHNE UMSCHLAG Bose, Carl August Graf Author: Bose, Carl August Graf Recipient: Haeckel, Ernst Dating: 13.03.1884
BRIEF OHNE UMSCHLAG Bose, Carl August Graf Author: Bose, Carl August Graf Recipient: Haeckel, Ernst Dating: 24.03.1884
BRIEF [O.A.] Hammerschmidt, Lotte Author: Hammerschmidt, Lotte Recipient: Haeckel, Ernst Dating: 05.12.1911
BRIEF [O.A.] Seilern, Therese [Gräfin] Author: Seilern, Therese [Gräfin] Recipient: Haeckel, Ernst Dating: 16.02.1914