BRIEF OHNE UMSCHLAG Dorsch, Hannah Author: Dorsch, Hannah Recipient: Haeckel, Ernst Dating: 14.02.1906
BRIEF OHNE UMSCHLAG Dorsch, Hannah Author: Dorsch, Hannah Recipient: Haeckel, Ernst Dating: 08.03.1906
BRIEF OHNE UMSCHLAG Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 15.02.1906
BRIEF OHNE UMSCHLAG Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 14.10.1906
BRIEF [O.A.] Bignamy, Enrico Author: Bignamy, Enrico Recipient: Haeckel, Ernst Corporation: "Coenobium" Revista Internationale Dating: 05.12.1906
BRIEF OHNE UMSCHLAG Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 20.06.1906