POSTKARTE Van de Velde-Sethe, Maria Author: Van de Velde-Sethe, Maria Recipient: Haeckel, Ernst Dating: 14.09.1902
POSTKARTE Bölsche, Johanna; Bölsche, Wilhelm Author: Bölsche, Johanna; Bölsche, Wilhelm Recipient: Haeckel, Ernst Dating: 03.11.1908
POSTKARTE Streichhan, Anna Marie Emma Author: Streichhan, Anna Marie Emma Recipient: Haeckel, Ernst Dating: 01.06.1918
POSTKARTE Streichhan, Anna Marie Emma Author: Streichhan, Anna Marie Emma Recipient: Haeckel, Ernst Dating: 18.05.1918