BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Linck, Gottlob Dating: 31.01.1913
BRIEF OHNE UMSCHLAG Bergner, Franz Author: Bergner, Franz Recipient: Haeckel, Ernst Dating: 03.03.1913
BRIEF OHNE UMSCHLAG Bergner, Franz Author: Bergner, Franz Recipient: Haeckel, Ernst Dating: 24.09.1913
BRIEF [O.A.] Recipient: Haeckel, Ernst Corporation: Apollowerk G.m.b.H., Kunstanstalt und Verlag Dating: 03.06.1913
BRIEF [O.A.] Recipient: Haeckel, Ernst Corporation: Apollowerk G.m.b.H., Kunstanstalt und Verlag Dating: 28.07.1913