BRIEF [O.A.] Bishop, Chas E... Author: Bishop, Chas E... Recipient: Haeckel, Ernst Corporation: Headquarters Ulysses S. Grant Post, No. 28 Dating: 03.04.1905
BRIEF OHNE UMSCHLAG Bender, Hedwig Author: Bender, Hedwig Recipient: Haeckel, Ernst Dating: 20.09.1905
BRIEF [O.A.] Borngräber, Otto Author: Borngräber, Otto Recipient: Haeckel, Ernst Corporation: Königlich Sächsisches Hoftheater Dating: 29.03.1905