BRIEF [O.A.] Henning, Max Author: Henning, Max Recipient: Haeckel, Ernst Corporation: Neuer Frankfurter Verlag G.m.b.H. Dating: 16.11.1912
BRIEF [O.A.] Winter, F... W... Author: Winter, F... W... Recipient: Haeckel, Ernst Dating: 14.01.1912