BRIEF [O.A.] Binet, René Author: Binet, René Recipient: Haeckel, Ernst Corporation: Ministère du Commerce, de l'Industrie, des Postes et des Télégraphes Dating: 21.03.1899
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 [O.A.] Binet, René Author: Binet, René Recipient: Haeckel, Ernst Corporation: Ministère du Commerce, de l'Industrie, des Postes et des Télégraphes Dating: 13.03.1900