BRIEF [O.A.] Kniesche, Elisabeth Author: Kniesche, Elisabeth Recipient: Haeckel, Ernst Dating: 06.03.1917
BRIEF [O.A.] Kilian, Waldemar C... Author: Kilian, Waldemar C... Recipient: Haeckel, Ernst Dating: 06.02.1917
BRIEF OHNE UMSCHLAG Pick, Klärchen Author: Pick, Klärchen Recipient: Haeckel, Ernst Dating: 07.03.1917
