BRIEF [O.A.] Haeckel, Ernst Author: Haeckel, Ernst Recipient: Uslar-Gleichen, Bernhard von Dating: 28.02.1916
BRIEF [O.A.] Haeckel, Ernst Author: Haeckel, Ernst Recipient: Uslar-Gleichen, Bernhard von Dating: 04.09.1916
BRIEF [O.A.] Haeckel, Ernst Author: Haeckel, Ernst Recipient: Uslar-Gleichen, Bernhard von Dating: 12.12.1916
BRIEF [O.A.] Greathouse, Bryan Author: Greathouse, Bryan Recipient: Haeckel, Ernst Dating: 28.01.1916