BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Gelzer, Heinrich Dating: Anfang 1888
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Michels, Victor Dating: 24.06.1916
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Hedemann, Wilhelm Dating: 31.05.1919
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Hedemann, Wilhelm Dating: 05.06.1919
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Maurer, Friedrich Dating: 19.02.1907
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Maurer, Friedrich Dating: 14.03.1907
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Binswanger, Otto Dating: 25.04.1911
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Linck, Gottlob Eduard Dating: 05.10.1912
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Linck, Gottlob Eduard Dating: 28.10.1912