BRIEF [O.A.] Neumann, Carl W... Author: Neumann, Carl W... Recipient: Haeckel, Ernst Dating: 10.02.1905
BRIEF [O.A.] Neumann, Carl W... Author: Neumann, Carl W... Recipient: Haeckel, Ernst Dating: 15.02.1905
BRIEF [O.A.] Recipient: Haeckel, Ernst Corporation: Deutscher Monistenbund, Ortsgruppe Kiel Dating: 27.02.1910
BRIEF [O.A.] Neumann, Carl W... Author: Neumann, Carl W... Recipient: Haeckel, Ernst Dating: 25.06.1905
BRIEF [O.A.] Neumann, Carl W... Author: Neumann, Carl W... Recipient: Haeckel, Ernst Dating: 21.09.1905
BRIEF [O.A.] Neumann, Carl W... Author: Neumann, Carl W... Recipient: Haeckel, Ernst Dating: 09.12.1905