BRIEF OHNE UMSCHLAG Anonym ("Veritas") Author: Anonym ("Veritas") Recipient: Haeckel, Ernst Dating: 30.12.1918
BRIEF OHNE UMSCHLAG Becker, Franz Johann Jakob Emil Author: Becker, Franz Johann Jakob Emil Recipient: Haeckel, Ernst Dating: 16.11.1918
BRIEF OHNE UMSCHLAG Almeroth, Hans Author: Almeroth, Hans Recipient: Haeckel, Ernst Dating: 11.02.1918
BRIEF OHNE UMSCHLAG Keller, Conrad Author: Keller, Conrad Recipient: Haeckel, Ernst Dating: 09.02.1918