POSTKARTE Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 25.02.1908
POSTKARTE Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 16.02.1912
POSTKARTE Engelsmann, Elisabeth Author: Engelsmann, Elisabeth Recipient: Haeckel, Ernst Dating: 16.02.1915