BRIEFENTWURF Haeckel, Ernst Author: Haeckel, Ernst Recipient: Cartellieri, Georg Maximilian Alexander Dating: 27.07.1914
BRIEFENTWURF Haeckel, Ernst Author: Haeckel, Ernst Recipient: Monaco, Albert I. Fürst von Dating: 08.12.1908
BRIEFENTWURF Haeckel, Ernst Author: Haeckel, Ernst Recipient: Watzdorf, Bernhard von [Staatsminister] Dating: 04.04.1863