BRIEF MIT UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Delle Grazie, Marie Eugenie Dating: 18.07.1906
PORTRÄTPOSTKARTE Haeckel, Ernst Author: Haeckel, Ernst Recipient: Delle Grazie, Marie Eugenie Dating: 04.02.1906
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Delle Grazie, Marie Eugenie Dating: 06.02.1906