BRIEF [O.A.] Janes, Lewis G... Author: Janes, Lewis G... Recipient: Haeckel, Ernst Corporation: The Brooklyn Ethical Association Dating: 14.11.1890
BRIEF OHNE UMSCHLAG Aderhold, Rudolf Author: Aderhold, Rudolf Recipient: Haeckel, Ernst Dating: 18.05.1890
BRIEF OHNE UMSCHLAG Aderhold, Rudolf Author: Aderhold, Rudolf Recipient: Haeckel, Ernst Dating: 29.10.1890