BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Heldburg, Helene Freifrau von Dating: 12.11.1889
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Heldburg, Helene Freifrau von Dating: 15.02.1891
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Heldburg, Helene Freifrau von Dating: 08.06.1889
