BRIEF [O.A.] Schewiakoff, W... Author: Schewiakoff, W... Recipient: Haeckel, Ernst Dating: 08.05.1903
BRIEF [O.A.] Schewiakoff, W... Author: Schewiakoff, W... Recipient: Haeckel, Ernst Dating: 20.09.1903
BRIEF [O.A.] Koehler, Albert Author: Koehler, Albert Recipient: Haeckel, Ernst Corporation: Flak Batt. 56 Dating: 25.03.1917
BRIEF [O.A.] Kaulbars, Nicolai [Baron] Author: Kaulbars, Nicolai [Baron] Recipient: Haeckel, Ernst Dating: 28.12.1874
BRIEF [O.A.] Rehbinder, Boris [Baron] Author: Rehbinder, Boris [Baron] Recipient: Haeckel, Ernst Dating: 09.04.1894