PORTRÄTPOSTKARTE Haeckel, Ernst Author: Haeckel, Ernst Recipient: Schweninger, Ernst Dating: 19.06.1911
PORTRÄTPOSTKARTE Haeckel, Walther Author: Haeckel, Walther Recipient: Haeckel, Ernst Dating: 05.12.1911
PORTRÄTPOSTKARTE Haeckel, Walther Author: Haeckel, Walther Recipient: Haeckel, Agnes Dating: 12.03.1911