BRIEF [O.A.] Eckert, Franziska Author: Eckert, Franziska Recipient: Haeckel, Ernst Dating: 13.03.1905
BRIEF [O.A.] Eckert, Franziska Author: Eckert, Franziska Recipient: Haeckel, Ernst Dating: 29.03.1905
BRIEF [O.A.] Jahn, Jaroslav J... Author: Jahn, Jaroslav J... Recipient: Haeckel, Ernst Corporation: Kaiserl. Königl. Geologische Reichsanstalt Dating: 31.01.1897
BRIEF [O.A.] Jahn, Jaroslav J... Author: Jahn, Jaroslav J... Recipient: Haeckel, Ernst Corporation: Mineralogicko-Geologicky Ustav Dating: 30.12.1899
