BRIEF [O.A.] Vogtherr, E... Author: Vogtherr, E... Recipient: Haeckel, Ernst Corporation: Bund freier religiöser Gemeinden Deutschlands Dating: 19.05.1906
BRIEF [O.A.] Haeckel, Heinrich Author: Haeckel, Heinrich Recipient: Haeckel, Ernst Dating: 27.12.1906
BRIEF [O.A.] Haeckel, Heinrich Author: Haeckel, Heinrich Recipient: Haeckel, Ernst Dating: 19.11.1906
BRIEF [O.A.] Haeckel, Heinrich Author: Haeckel, Heinrich Recipient: Haeckel, Ernst Dating: 04.09.1906
BRIEF [O.A.] Haeckel, Heinrich Author: Haeckel, Heinrich Recipient: Haeckel, Ernst Dating: 08.08.1906