BRIEF [O.A.] Keller-Leuzinger, Franz Author: Keller-Leuzinger, Franz Recipient: Haeckel, Ernst Dating: 15.06.1882
BRIEF [O.A.] Keller-Leuzinger, Franz Author: Keller-Leuzinger, Franz Recipient: Haeckel, Ernst Dating: 30.06.1882
BRIEF [O.A.] Keller-Leuzinger, Franz Author: Keller-Leuzinger, Franz Recipient: Haeckel, Ernst Dating: 03.09.1882
BRIEF [O.A.] Keller-Leuzinger, Franz Author: Keller-Leuzinger, Franz Recipient: Haeckel, Ernst Dating: 26.09.1882
BRIEF [O.A.] Keller-Leuzinger, Franz Author: Keller-Leuzinger, Franz Recipient: Haeckel, Ernst Dating: 06.10.1882
BRIEF [O.A.] Keller-Leuzinger, Franz Author: Keller-Leuzinger, Franz Recipient: Haeckel, Ernst Dating: 09.10.1882
BRIEF [O.A.] Keller-Leuzinger, Franz Author: Keller-Leuzinger, Franz Recipient: Haeckel, Ernst Dating: 16.10.1882
