BRIEF OHNE UMSCHLAG Ankenbrand, Ludwig Author: Ankenbrand, Ludwig Recipient: Haeckel, Ernst Corporation: Gesundes Leben Dating: 04.11.1910
BRIEF OHNE UMSCHLAG Aigner, Eduard Author: Aigner, Eduard Recipient: Haeckel, Ernst Dating: 31.10.1910
POSTKARTE Babinger, Franz H... Author: Babinger, Franz H... Recipient: Haeckel, Ernst Dating: 11.02.1910
BRIEF [O.A.] Basset, C... Author: Basset, C... Recipient: Haeckel, Ernst Corporation: C. Basset, Import schwedischer Zimmertüren Dating: 18.02.1910