BRIEF [O.A.] Einstein, Leopold Author: Einstein, Leopold Recipient: Haeckel, Ernst Dating: 13.01.1882
BRIEF [O.A.] Einstein, Leopold Author: Einstein, Leopold Recipient: Haeckel, Ernst Dating: 20.11.1882
BRIEF [O.A.] Einstein, Leopold Author: Einstein, Leopold Recipient: Haeckel, Ernst Dating: 09.04.1885
BRIEF [O.A.] Einstein, Leopold Author: Einstein, Leopold Recipient: Haeckel, Ernst Corporation: Volapükaklub Dating: 24.04.1885
BRIEF [O.A.] Einstein, Leopold Author: Einstein, Leopold Recipient: Haeckel, Ernst Corporation: Volapükaklub Dating: 1885.06.?? [?]
BRIEF [O.A.] Kämmerer, G... Author: Kämmerer, G... Recipient: Haeckel, Ernst Corporation: Freie religiöse Gemeinde Nürnberg Dating: 20.12.1905
BRIEF [O.A.] Rindskopf, Sigmund Author: Rindskopf, Sigmund Recipient: Haeckel, Ernst Dating: 21.06.1903
