ANSICHTSKARTE Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 16.03.1903
ANSICHTSKARTE Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 28.12.1907
ANSICHTSKARTE Becker, Franz Johann Jakob Emil Author: Becker, Franz Johann Jakob Emil Recipient: Haeckel, Ernst Dating: 1916