BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Heinrich Dating: 23.11.1918
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Heinrich Dating: 17.02.1919
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Heinrich Dating: 20.12.1897
BRIEF OHNE UMSCHLAG Haeckel, Karl Author: Haeckel, Karl Recipient: Haeckel, Heinrich Dating: 01.09.1897
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Heinrich Dating: 13.02.1899
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Heinrich Dating: 23.09.1911
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Heinrich Dating: 16.02.1916