BRIEF [O.A.] Chevais, Maurice Author: Chevais, Maurice Recipient: Haeckel, Ernst Corporation: Féderation Internationale de La Pensée Dating: 17.10.1905
BRIEF [O.A.] Gsell, Paul Author: Gsell, Paul Recipient: Haeckel, Ernst Corporation: La Revue Dating: 11.09.1905
BRIEF OHNE UMSCHLAG Altmann-Bronn, Ida Author: Altmann-Bronn, Ida Recipient: Haeckel, Ernst Dating: 31.08.1905
BRIEF [O.A.] Schleicher, Fréres Author: Schleicher, Fréres Recipient: Haeckel, Ernst Dating: 25.02.1905
BRIEF [O.A.] Schleicher, Fréres Author: Schleicher, Fréres Recipient: Haeckel, Ernst Dating: 04.01.1905
BRIEF [O.A.] Schleicher, Fréres Author: Schleicher, Fréres Recipient: Haeckel, Ernst Dating: 26.01.1905
BRIEF [O.A.] Schleicher, Fréres Author: Schleicher, Fréres Recipient: Haeckel, Ernst Dating: 04.02.1905
BRIEF [O.A.] Schleicher, Fréres Author: Schleicher, Fréres Recipient: Haeckel, Ernst Dating: 22.02.1905
BRIEF [O.A.] Schleicher, Fréres Author: Schleicher, Fréres Recipient: Haeckel, Ernst Dating: 17.03.1905