BILDPOSTKARTE Kraigher-Porges, Josepha Author: Kraigher-Porges, Josepha Recipient: Haeckel, Ernst Dating: 06.07.1900
BILDPOSTKARTE Crompton, Ella von Author: Crompton, Ella von Recipient: Haeckel, Ernst Dating: 15.08.1917
BILDPOSTKARTE Krauseneck, Gustav Adolf Author: Krauseneck, Gustav Adolf Recipient: Haeckel, Ernst Dating: 03.09.1910