BRIEF OHNE UMSCHLAG Bölsche, Wilhelm Author: Bölsche, Wilhelm Recipient: Haeckel, Ernst Dating: 02.07.1915
BRIEF OHNE UMSCHLAG Bölsche, Wilhelm Author: Bölsche, Wilhelm Recipient: Haeckel, Ernst Dating: 17.12.1915
TELEGRAMM Heldburg, Helene Freifrau von Author: Heldburg, Helene Freifrau von Recipient: Haeckel, Ernst Dating: 16.02.1915
BRIEF [O.A.] Schleipfer, August Author: Schleipfer, August Recipient: Haeckel, Ernst Corporation: Thüringer Marmor ... Industrie Dating: 04.05.1915
BRIEF [O.A.] Schlesinger, Louis Author: Schlesinger, Louis Recipient: Haeckel, Ernst Dating: 11.08.1915
BRIEF [O.A.] Schlichting, Marie Author: Schlichting, Marie Recipient: Haeckel, Ernst Dating: 19.02.1915