BRIEF OHNE UMSCHLAG Bülow, Paula von Author: Bülow, Paula von Recipient: Haeckel, Ernst Dating: ??.06.1912
BRIEF [O.A.] Langenhan, Gabriele Author: Langenhan, Gabriele Recipient: Haeckel, Ernst Dating: 11.08.1912
BRIEF OHNE UMSCHLAG Müller, Alexandrine Author: Müller, Alexandrine Recipient: Haeckel, Ernst Dating: 20.02.1912
BRIEF OHNE UMSCHLAG Müller, Alexandrine Author: Müller, Alexandrine Recipient: Haeckel, Ernst Dating: 09.03.1912
BRIEF OHNE UMSCHLAG Müller, Alexandrine Author: Müller, Alexandrine Recipient: Haeckel, Ernst Dating: 10.02.1912
BRIEF OHNE UMSCHLAG Müller, Alfred Author: Müller, Alfred Recipient: Haeckel, Ernst Dating: 13.02.1912