BRIEF [O.A.] Cintra, L... C... Coelho Author: Cintra, L... C... Coelho Recipient: Haeckel, Ernst Corporation: Brazil-Mental Dating: 05.05.1908
BRIEF [O.A.] Knieling, Johs... W... Author: Knieling, Johs... W... Recipient: Haeckel, Ernst Dating: 27.06.1914
BRIEF OHNE UMSCHLAG Ihering, Hermann von Author: Ihering, Hermann von Recipient: Haeckel, Ernst Corporation: Museu Paulista Dating: 19.09.1904
BRIEF OHNE UMSCHLAG Ihering, Hermann von Author: Ihering, Hermann von Recipient: Haeckel, Ernst Corporation: Museu Paulista Dating: 03.08.1905
BRIEF OHNE UMSCHLAG Ihering, Hermann von Author: Ihering, Hermann von Recipient: Haeckel, Ernst Corporation: Museu Paulista Dating: 10.05.1906
BILDPOSTKARTE Ihering, Hermann von Author: Ihering, Hermann von Recipient: Haeckel, Ernst Dating: 23.04.1907
BRIEF OHNE UMSCHLAG Ihering, Hermann von Author: Ihering, Hermann von Recipient: Haeckel, Ernst Corporation: Museu Paulista Dating: 24.06.1908
BRIEF OHNE UMSCHLAG Ihering, Hermann von Author: Ihering, Hermann von Recipient: Haeckel, Ernst Corporation: Museu Paulista Dating: 22.04.1909