BRIEF [O.A.] Schoeller, Eugenie Author: Schoeller, Eugenie Recipient: Haeckel, Ernst Dating: 24.01.1916
BRIEF [O.A.] Schoeller, Eugenie Author: Schoeller, Eugenie Recipient: Haeckel, Ernst Dating: 18.06.1916
BRIEF [O.A.] Schoeller, Eugenie Author: Schoeller, Eugenie Recipient: Haeckel, Ernst Dating: 28.04.1918