BRIEF OHNE UMSCHLAG Starck, Emilie Author: Starck, Emilie Recipient: Haeckel, Ernst Dating: 18.07.1910
BRIEF OHNE UMSCHLAG Lilienthal-Stern, Meta Author: Lilienthal-Stern, Meta Recipient: Haeckel, Ernst Dating: 17.08.1910
GRUSSADRESSE Berg, John [et al.] Author: Berg, John [et al.] Recipient: Haeckel, Ernst Corporation: Repraesentanten des Finnischen Volkes in Chicago Dating: 24.06.1910