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