BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Rottenburg, Paul von Dating: 20.08.1899
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Rottenburg, Paul von Dating: 16.10.1901
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Rottenburg, Paul von Dating: 22.09.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Rottenburg, Paul von Dating: 03.09.1890