BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: de Gruyter, Walter Dating: 04.08.1918
BRIEF OHNE UMSCHLAG Benedikt, Moritz Author: Benedikt, Moritz Recipient: Haeckel, Ernst Dating: 28.01.1918
BRIEF OHNE UMSCHLAG Benedikt, Moritz Author: Benedikt, Moritz Recipient: Haeckel, Ernst Dating: 31.01.1918
POSTKARTE Becker, Franz Johann Jakob Emil Author: Becker, Franz Johann Jakob Emil Recipient: Haeckel, Ernst Dating: 11.04.1918
BRIEF OHNE UMSCHLAG Becker, Franz Johann Jakob Emil Author: Becker, Franz Johann Jakob Emil Recipient: Haeckel, Ernst Dating: 16.11.1918
BRIEF [O.A.] Blücher, Ingeborg von Author: Blücher, Ingeborg von Recipient: Haeckel, Ernst Dating: 23.02.1918
BRIEF [O.A.] Berger, Elise Author: Berger, Elise Recipient: Haeckel, Ernst Corporation: Königl. Wilhelma Dating: 14.02.1918