POSTKARTE Krauseneck, Valentine Author: Krauseneck, Valentine Recipient: Haeckel, Ernst Dating: 30.12.1904
BRIEF [O.A.] Krauseneck, Valentine Author: Krauseneck, Valentine Recipient: Haeckel, Ernst Dating: 12.02.1904
BRIEF [O.A.] Krauseneck, Valentine Author: Krauseneck, Valentine Recipient: Haeckel, Ernst Dating: 29.07.1904