BRIEF [O.A.] Halpin, Druitt Author: Halpin, Druitt Recipient: Haeckel, Ernst Corporation: Thermal Storage Ltd. Dating: 15.07.1903
BRIEF [O.A.] Graeser, Emma Author: Graeser, Emma Recipient: Haeckel, Ernst Corporation: Verlagsbuchhandlung Carl Graeser & Co. Dating: 22.06.1903
BRIEF [O.A.] Schewiakoff, W... Author: Schewiakoff, W... Recipient: Haeckel, Ernst Dating: 08.05.1903
BRIEF [O.A.] Schewiakoff, W... Author: Schewiakoff, W... Recipient: Haeckel, Ernst Dating: 20.09.1903
BRIEF [O.A.] Hanitsch, Richard Author: Hanitsch, Richard Recipient: Haeckel, Ernst Dating: 22.11.1903
