BRIEF [O.A.] Flothuis, M... H... Author: Flothuis, M... H... Recipient: Haeckel, Ernst Dating: 01.01.1912
BRIEF [O.A.] Flothuis, M... H... Author: Flothuis, M... H... Recipient: Haeckel, Ernst Dating: 29.01.1912
BRIEF [O.A.] Flothuis, M... H... Author: Flothuis, M... H... Recipient: Haeckel, Ernst Dating: 14.02.1912
BRIEF [O.A.] Flothuis, M... H... Author: Flothuis, M... H... Recipient: Haeckel, Ernst Dating: 29.12.1912