BRIEF [O.A.] Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Carl & Charlotte [Eltern] Dating: 19.12.1870
BRIEF [O.A.] Hohenbühel-Heufler, Ludwig Author: Hohenbühel-Heufler, Ludwig Recipient: Haeckel, Ernst Dating: 26.10.1870
BRIEF [O.A.] Hohenbühel-Heufler, Ludwig Author: Hohenbühel-Heufler, Ludwig Recipient: Haeckel, Ernst Dating: 18.11.1870
BRIEF [O.A.] Hertzka, Theodor Author: Hertzka, Theodor Recipient: Haeckel, Ernst Corporation: Neue Freie Presse, Redaction Dating: 14.07.1870