BRIEF OHNE UMSCHLAG Foerster, Wilhelm Author: Foerster, Wilhelm Recipient: Haeckel, Ernst Dating: 24.06.1893
BRIEF OHNE UMSCHLAG Foerster, Wilhelm Author: Foerster, Wilhelm Recipient: Haeckel, Ernst Dating: 21.04.1893
BRIEF [O.A.] Foerster, Wilhelm Author: Foerster, Wilhelm Recipient: Haeckel, Ernst Dating: 19.07.1893