BRIEF [O.A.] Ivezic, Gerassim P... Author: Ivezic, Gerassim P... Recipient: Haeckel, Ernst Dating: 15.02.1907
BRIEF [O.A.] Ivezic, Gerassim P... Author: Ivezic, Gerassim P... Recipient: Haeckel, Ernst Dating: 31.12.1907
BRIEF [O.A.] Steinmetz, Johann Karl Author: Steinmetz, Johann Karl Recipient: Haeckel, Ernst Dating: 30.11.1907
BRIEF [O.A.] Steinmetz, Johann Karl Author: Steinmetz, Johann Karl Recipient: Haeckel, Ernst Dating: 10.12.1907