BRIEF [O.A.] Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 30.12.1911
POSTKARTE Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 16.02.1912
BRIEF [O.A.] Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 15.02.1913
BRIEF [O.A.] Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 30.12.1913
BRIEF [O.A.] Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 16.02.1914
POSTKARTE Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 16.02.1915
BRIEF [O.A.] Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 10.09.1906
BRIEF [O.A.] Gmelin, Johann Georg Author: Gmelin, Johann Georg Recipient: Haeckel, Ernst Dating: 05.09.1909
BRIEF [O.A.] Georgii, Eberhard Author: Georgii, Eberhard Recipient: Haeckel, Ernst Dating: 15.02.1904
BRIEF [O.A.] Grün, Robb... S... Author: Grün, Robb... S... Recipient: Haeckel, Ernst Dating: 09.01.1893