BRIEF OHNE UMSCHLAG Schmidt, Heinrich Author: Schmidt, Heinrich Recipient: Haeckel, Ernst Dating: 22.06.1914
BRIEF OHNE UMSCHLAG Schmidt, Heinrich Author: Schmidt, Heinrich Recipient: Haeckel, Ernst Dating: 25.07.1916
BRIEF OHNE UMSCHLAG Schmidt, Heinrich Author: Schmidt, Heinrich Recipient: Haeckel, Ernst Dating: 28.06.1916
BRIEF OHNE UMSCHLAG Schmidt, Heinrich Author: Schmidt, Heinrich Recipient: Haeckel, Ernst Dating: 26.03.1899
BRIEFENTWURF Schmidt, Heinrich Author: Schmidt, Heinrich Recipient: Haeckel, Ernst Dating: 27.07.1909
BRIEF [O.A.] Schmidt, Heinrich Author: Schmidt, Heinrich Recipient: Haeckel, Ernst Dating: 19.02.1904
BRIEF [O.A.] Schmidt, Heinrich Author: Schmidt, Heinrich Recipient: Haeckel, Ernst Dating: 06.04.1904