BRIEF [O.A.] Kellner, Heinrich Author: Kellner, Heinrich Recipient: Haeckel, Ernst Dating: 22.07.1908
BRIEF [O.A.] Kellogg, Vernon Lyman Author: Kellogg, Vernon Lyman Recipient: Haeckel, Ernst Dating: 15.11.1908
BRIEF [O.A.] Kellogg, Vernon Lyman Author: Kellogg, Vernon Lyman Recipient: Haeckel, Ernst Dating: 22.11.1908
BRIEF OHNE UMSCHLAG Bernardelli, Paul Author: Bernardelli, Paul Recipient: Haeckel, Ernst Dating: 06.09.1908