KARTE Haeckel, Ernst; Mulder, Lodewijk [et al.] Author: Haeckel, Ernst; Mulder, Lodewijk [et al.] Recipient: Sethe, Bertha Dating: 31.08.1898
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Sethe, Bertha Dating: ca. 24.01.1886
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Sethe, Bertha Dating: 08.08.1892
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Sethe, Bertha Dating: 27.12.1859