BRIEF OHNE UMSCHLAG Scheffauer, Herman Author: Scheffauer, Herman Recipient: Haeckel, Ernst Dating: 09.05.1915
BRIEF [O.A.] Flothuis, M... H... Author: Flothuis, M... H... Recipient: Haeckel, Ernst Dating: 14.02.1915
BRIEF [O.A.] Flothuis, M... H... Author: Flothuis, M... H... Recipient: Haeckel, Ernst Dating: 29.12.1915
BRIEF [O.A.] Weber van Bosse, Anna Author: Weber van Bosse, Anna Recipient: Haeckel, Ernst Dating: 09.05.1915