BRIEF [O.A.] Gaedertz, Karl Theodor Author: Gaedertz, Karl Theodor Recipient: Haeckel, Ernst Dating: 03.09.1901
BRIEF [O.A.] Krannhals, Woldemar Alexander Author: Krannhals, Woldemar Alexander Recipient: Haeckel, Ernst Dating: 15.02.1915
BRIEF [O.A.] Krannhals, Woldemar Alexander Author: Krannhals, Woldemar Alexander Recipient: Haeckel, Ernst Dating: 05.03.1917
BRIEF [O.A.] Krannhals, Woldemar Alexander Author: Krannhals, Woldemar Alexander Recipient: Haeckel, Ernst Dating: 14.02.1918
BRIEF [O.A.] Krannhals, Woldemar Alexander Author: Krannhals, Woldemar Alexander Recipient: Haeckel, Ernst Dating: 14.02.1919
POSTKARTE Krannhals, Woldemar Alexander Author: Krannhals, Woldemar Alexander Recipient: Haeckel, Ernst