TELEGRAMM Heldburg, Helene Freifrau von Author: Heldburg, Helene Freifrau von Recipient: Haeckel, Ernst Dating: 01.01.1899
TELEGRAMM Heldburg, Helene Freifrau von Author: Heldburg, Helene Freifrau von Recipient: Haeckel, Ernst Dating: 03.08.1899
TELEGRAMM Capellini, Giovanni Author: Capellini, Giovanni Recipient: Haeckel, Ernst Dating: 13.10.1899