BRIEF [O.A.] Eberle, Cyprian Author: Eberle, Cyprian Recipient: Haeckel, Ernst Corporation: Monistischer Lesekreis Ulm Dating: 22.05.1904
BRIEF [O.A.] Eberle, Cyprian Author: Eberle, Cyprian Recipient: Haeckel, Ernst Corporation: Monistischer Lesekreis Ulm Dating: 10.11.1904
BRIEF [O.A.] Eberle, Cyprian Author: Eberle, Cyprian Recipient: Haeckel, Ernst Corporation: Monistischer Lesekreis Ulm Dating: 29.11.1904