WIDMUNG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Lubosch, Wilhelm Dating: 1918.??.?? [Frühjahr]
WIDMUNG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Josefa (geb. Scholz) Dating: 05.08.1905
WIDMUNG Breitenbach, Wilhelm Author: Breitenbach, Wilhelm Recipient: Haeckel, Ernst Dating: 18.04.1910