BRIEF [O.A.] Schepotieff, Alexander Author: Schepotieff, Alexander Recipient: Haeckel, Ernst Dating: 01.04.1912
BRIEF [O.A.] Schewiakoff, Wladimir von Author: Schewiakoff, Wladimir von Recipient: Haeckel, Ernst Dating: 31.10.1902
BRIEF [O.A.] Lamarlinghi [Baronessa] Author: Lamarlinghi [Baronessa] Recipient: Haeckel, Ernst Dating: 12.10.1909
BRIEF [O.A.] Lorenzo, Giuseppe de Author: Lorenzo, Giuseppe de Recipient: Haeckel, Ernst Dating: 27.09.1893
BRIEF [O.A.] Montefusio, Alfonso Author: Montefusio, Alfonso Recipient: Haeckel, Ernst Dating: 02.07.1882
BRIEF [O.A.] Donvito, Eduardo Author: Donvito, Eduardo Recipient: Haeckel, Ernst Corporation: Il Pubblicista - La Gioventù Dating: 02.04.1912