BRIEF [O.A.] Krauseneck, Heinrich Author: Krauseneck, Heinrich Recipient: Haeckel, Ernst Dating: 06.04.1886
BRIEF [O.A.] Krauseneck, Heinrich Author: Krauseneck, Heinrich Recipient: Haeckel, Ernst Dating: 27.05.1886
BRIEF [O.A.] Krauseneck, Heinrich Author: Krauseneck, Heinrich Recipient: Haeckel, Ernst Dating: 25.10.1886
BRIEF [O.A.] Krauseneck, Heinrich Author: Krauseneck, Heinrich Recipient: Haeckel, Ernst Dating: 30.12.1886
BRIEF [O.A.] Krauseneck, Heinrich Author: Krauseneck, Heinrich Recipient: Haeckel, Ernst Dating: 12.04.1886