BRIEF [O.A.] Osterwald, Wilhelm Author: Osterwald, Wilhelm Recipient: Haeckel, Carl Gottlob Dating: 06.03.1852
BRIEF OHNE UMSCHLAG Karo, Adalbert Author: Karo, Adalbert Recipient: Haeckel, Carl Gottlob Dating: 04.03.1864
BRIEF OHNE UMSCHLAG Osterwald, Wilhelm Author: Osterwald, Wilhelm Recipient: Haeckel, Carl Gottlob Dating: 26.09.1855
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Carl Gottlob Dating: 15.10.1851