BRIEF OHNE UMSCHLAG Hertwig, Oscar Author: Hertwig, Oscar Recipient: Haeckel, Ernst Dating: 10.11.1904
BRIEF OHNE UMSCHLAG Hertwig, Oscar Author: Hertwig, Oscar Recipient: Haeckel, Ernst Dating: 20.11.1901
BRIEF OHNE UMSCHLAG Hertwig, Oscar Author: Hertwig, Oscar Recipient: Haeckel, Ernst Dating: 14.02.1904
BRIEF [O.A.] Harden, Maximilian Author: Harden, Maximilian Recipient: Haeckel, Ernst Dating: 30.04.1903
BRIEF [O.A.] Harden, Maximilian Author: Harden, Maximilian Recipient: Haeckel, Ernst Corporation: Die Zukunft Dating: 11.12.1903
POSTKARTE Harden, Maximilian Author: Harden, Maximilian Recipient: Haeckel, Ernst Corporation: Die Zukunft Dating: 14.02.1904
BRIEF [O.A.] Harden, Maximilian Author: Harden, Maximilian Recipient: Haeckel, Ernst Corporation: Die Zukunft Dating: 07.05.1904
BRIEF [O.A.] Harden, Maximilian Author: Harden, Maximilian Recipient: Haeckel, Ernst Dating: 22.01.1905
