BRIEF [O.A.] Aszlányi, Desider Author: Aszlányi, Desider Recipient: Haeckel, Ernst Dating: 03.11.1911
BRIEF OHNE UMSCHLAG Aszlányi, Desider Author: Aszlányi, Desider Recipient: Haeckel, Ernst Dating: 21.10.1911
BRIEF [O.A.] Aszlányi, Desider Author: Aszlányi, Desider Recipient: Haeckel, Ernst Dating: 06.12.1911
BILDPOSTKARTE Baracs, Karl; Baracs, Paula; Bothe, Margarethe Author: Baracs, Karl; Baracs, Paula; Bothe, Margarethe Recipient: Haeckel, Ernst Dating: 14.02.1916
BILDPOSTKARTE Baracs, Karl; Baracs, Paula Author: Baracs, Karl; Baracs, Paula Recipient: Haeckel, Ernst Dating: 06.09.1916