BRIEF OHNE UMSCHLAG Hatschek, Berthold Author: Hatschek, Berthold Recipient: Haeckel, Ernst Dating: 15.04.1918
BRIEF OHNE UMSCHLAG Hatschek, Berthold Author: Hatschek, Berthold Recipient: Haeckel, Ernst Dating: 02.06.1918
BRIEF OHNE UMSCHLAG Hatschek, Berthold Author: Hatschek, Berthold Recipient: Haeckel, Ernst Dating: 24.06.1918
BRIEF OHNE UMSCHLAG Hatschek, Berthold Author: Hatschek, Berthold Recipient: Haeckel, Ernst Dating: 12.07.1918