BRIEF [O.A.] Schimmelmann, Frh. Hugo von Author: Schimmelmann, Frh. Hugo von Recipient: Haeckel, Ernst Dating: 15.02.1909
BRIEF [O.A.] Jubelt, R... K... Reinhold Author: Jubelt, R... K... Reinhold Recipient: Haeckel, Ernst Dating: ??.02.1909