BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 13.02.1871
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 13.08.1873
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 28.10.1873
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 09.07.1874
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 15.06.1875
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 29.12.1875
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 26.06.1877
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 30.06.1877
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 11.07.1877
BRIEF [O.A.] Zittel, Karl Alfred von Author: Zittel, Karl Alfred von Recipient: Haeckel, Ernst Dating: 20.11.1877
