BRIEF [O.A.] Theszóll, Charles Author: Theszóll, Charles Recipient: Haeckel, Ernst Dating: 23-02-1900
BRIEF [O.A.] Deregi, Oskar Author: Deregi, Oskar Recipient: Haeckel, Ernst Corporation: Nemzeti Szinház Dating: 11.09.1904
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