BRIEF [O.A.] Bibaud, J... J... E... Author: Bibaud, J... J... E... Recipient: Haeckel, Ernst Dating: 14.09.1912
BRIEF [O.A.] Bibits, Sofie von ... Author: Bibits, Sofie von ... Recipient: Haeckel, Ernst Dating: 26.03.1912
BRIEF OHNE UMSCHLAG Bernstein, Herman Author: Bernstein, Herman Recipient: Haeckel, Ernst Corporation: The New-York Sun Dating: 16.06.1912
BRIEF OHNE UMSCHLAG Ammon, Sophie von Author: Ammon, Sophie von Recipient: Haeckel, Ernst Dating: 10.02.1912
BRIEF [O.A.] Baumann, Friedrich Author: Baumann, Friedrich Recipient: Haeckel, Ernst Dating: 18.01.1912
BRIEF [O.A.] Beadnell, C... Marsh... Author: Beadnell, C... Marsh... Recipient: Haeckel, Ernst Corporation: H. M. S. Fisgard Dating: 25.02.1912
