BRIEF [O.A.] Cless, Alfred Martin Author: Cless, Alfred Martin Recipient: Haeckel, Ernst Dating: 24.03.1900
BRIEF [O.A.] Kellogg, Vernon Lyman Author: Kellogg, Vernon Lyman Recipient: Haeckel, Ernst Corporation: Leland Stanford University Dating: ??.12.1894
BRIEF OHNE UMSCHLAG Scheffauer, Herman Author: Scheffauer, Herman Recipient: Haeckel, Ernst Dating: 13.01.1909
BRIEF OHNE UMSCHLAG Scheffauer, Herman Author: Scheffauer, Herman Recipient: Haeckel, Ernst Dating: 13.04.1909
BRIEF OHNE UMSCHLAG Scheffauer, Herman Author: Scheffauer, Herman Recipient: Haeckel, Ernst Dating: 31.05.1909
UMSCHLAG Darling, Ernest Willing Author: Darling, Ernest Willing Recipient: Haeckel, Ernst Dating: 26.04.1914
BRIEF [O.A.] Belford, Robert J... Author: Belford, Robert J... Recipient: Haeckel, Ernst Corporation: Typewriter Silencer Mfrs. Dating: 25.03.1912
BRIEF [O.A.] Belford, Robert J. Author: Belford, Robert J. Recipient: Haeckel, Ernst Corporation: Typewriter Silencer Mfrs. Dating: 14.06.1912