BRIEF [O.A.] Krauseneck, Heinrich Author: Krauseneck, Heinrich Recipient: Haeckel, Ernst Dating: 01.01.1894
BRIEF [O.A.] Krauseneck, Heinrich Author: Krauseneck, Heinrich Recipient: Haeckel, Ernst Dating: 28.02.1894
BRIEF [O.A.] Krauseneck, Heinrich Author: Krauseneck, Heinrich Recipient: Haeckel, Ernst Dating: 29.07.1894