BILDPOSTKARTE Becker, Franz Johann Jakob Emil Author: Becker, Franz Johann Jakob Emil Recipient: Haeckel, Ernst Dating: 20.08.1917
BILDPOSTKARTE Becker, Franz Johann Jakob Emil Author: Becker, Franz Johann Jakob Emil Recipient: Haeckel, Ernst Dating: ??.??.1913
BILDPOSTKARTE Kraigher-Porges, Josepha Author: Kraigher-Porges, Josepha Recipient: Haeckel, Ernst Dating: 31.03.1902
BILDPOSTKARTE Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 01.08.1898
BILDPOSTKARTE Sarasin, Paul; Sarasin, Fritz Author: Sarasin, Paul; Sarasin, Fritz Recipient: Haeckel, Ernst Dating: 12.06.1910