BRIEF [O.A.] Feichtinger, Alexius Baron Author: Feichtinger, Alexius Baron Recipient: Haeckel, Ernst Dating: 09.02.1914
BRIEF [O.A.] Caniy, W... [?] Author: Caniy, W... [?] Recipient: Haeckel, Ernst Corporation: Vallás és Közoktatásügyi Dating: 07.10.1896
BRIEF [O.A.] Dolezsalek, Anton Author: Dolezsalek, Anton Recipient: Haeckel, Ernst Dating: 03.04.1908