BRIEF [O.A.] Korvenkontio, Valio Author: Korvenkontio, Valio Recipient: Haeckel, Ernst Dating: 19.04.1908
BRIEF [O.A.] Kaulbars, Nicolai [Baron] Author: Kaulbars, Nicolai [Baron] Recipient: Haeckel, Ernst Dating: 21.12.1897