BRIEF [O.A.] Haeckel, Charlotte Author: Haeckel, Charlotte Recipient: Haeckel, Ernst Dating: 02.02.1870
BRIEF [O.A.] Haeckel, Charlotte Author: Haeckel, Charlotte Recipient: Haeckel, Ernst Dating: 30.10.1864
BRIEF [O.A.] Haeckel, Charlotte Author: Haeckel, Charlotte Recipient: Haeckel, Ernst Dating: 10.09.1876
BRIEF [O.A.] Haeckel, Charlotte Author: Haeckel, Charlotte Recipient: Haeckel, Ernst Dating: 15.01.1876