BRIEF [O.A.] Frenkel, Ferdinand Author: Frenkel, Ferdinand Recipient: Haeckel, Ernst Dating: 14.12.1873
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: ??.??.1876
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 25.01.1877
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 18.10.1877
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 06.01.1878
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 20.07.1878
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 03.01.1879
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 07.03.1879
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 17.02.1870
BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 07.06.1872