BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Grober, Julius Dating: 17.03.1908
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Grober, Julius Dating: 01.11.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Grober, Julius Dating: 30.04.1917
BRIEF OHNE UMSCHLAG Lehmann-Russbüldt, Otto Author: Lehmann-Russbüldt, Otto Recipient: Haeckel, Ernst Corporation: Giordano-Bruno-Bund Dating: 02.01.1903
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Grober, Julius Dating: 25.07.1917
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Breitenbach, Wilhelm Dating: 14.05.1906
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Breitenbach, Wilhelm Dating: 19.08.1906
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Breitenbach, Wilhelm Dating: 02.09.1906