POSTKARTE Wereschtschagin, Wassili Author: Wereschtschagin, Wassili Recipient: Haeckel, Ernst Dating: 27.03.1901
BRIEF [O.A.] Schild, Johann Author: Schild, Johann Recipient: Haeckel, Ernst Corporation: Deutsch-Australische-Dampfschiffs-Gesellschaft Dating: 13.03.1901
BRIEF OHNE UMSCHLAG Becker, Daniel Georg Author: Becker, Daniel Georg Recipient: Haeckel, Ernst Dating: 02.11.1901
BRIEF OHNE UMSCHLAG Becker, Daniel Georg Author: Becker, Daniel Georg Recipient: Haeckel, Ernst Dating: 05.12.1901
BRIEF [O.A.] Anton, Günther Kurt Author: Anton, Günther Kurt Recipient: Haeckel, Ernst Dating: 03.01.1901
BRIEF [O.A.] Anton, Günther Kurt Author: Anton, Günther Kurt Recipient: Haeckel, Ernst Corporation: Tjia King Lok Dating: 15.01.1901