BRIEF OHNE UMSCHLAG Bohle, Philipp Author: Bohle, Philipp Recipient: Haeckel, Ernst Dating: 29.08.1912
BRIEF [O.A.] Blume-Trenn, Magdalena Author: Blume-Trenn, Magdalena Recipient: Haeckel, Ernst Dating: 28.08.1905
BRIEF [O.A.] Blume-Trenn, Magdalena Author: Blume-Trenn, Magdalena Recipient: Haeckel, Ernst Dating: 11.09.1905
BRIEF [O.A.] Blume-Trenn, Magdalena Author: Blume-Trenn, Magdalena Recipient: Haeckel, Ernst Dating: 27.09.1905