POSTKARTE Breitenbach, Wilhelm Author: Breitenbach, Wilhelm Recipient: Haeckel, Ernst Corporation: Neue Weltanschauung Dating: 12.11.1910
POSTKARTE Breitenbach, Wilhelm Author: Breitenbach, Wilhelm Recipient: Haeckel, Ernst Corporation: Neue Weltanschauung Dating: 08.10.1910
POSTKARTE Focke, Wilhelm Olbers Author: Focke, Wilhelm Olbers Recipient: Haeckel, Ernst Dating: 20.05.1910
POSTKARTE Focke, Wilhelm Olbers Author: Focke, Wilhelm Olbers Recipient: Haeckel, Ernst Dating: 22.12.1910