POSTKARTE Thoden van Velzen, S... K... Author: Thoden van Velzen, S... K... Recipient: Haeckel, Ernst Dating: 13.02.1917
BRIEF MIT UMSCHLAG Thoden van Velzen, Syo Kornelius Author: Thoden van Velzen, Syo Kornelius Recipient: Haeckel, Ernst Dating: 15.02.1917
TELEGRAMM Thoden van Velzen, S... K... Author: Thoden van Velzen, S... K... Recipient: Haeckel, Ernst Dating: 16.02.1917
BRIEF [O.A.] Thoden van Velzen, S... K... Author: Thoden van Velzen, S... K... Recipient: Haeckel, Ernst Dating: 28.06.1917
BRIEF [O.A.] Thoden van Velzen, S... K... Author: Thoden van Velzen, S... K... Recipient: Haeckel, Ernst Dating: 23.08.1917
POSTKARTE Thoden van Velzen, S... K... Author: Thoden van Velzen, S... K... Recipient: Haeckel, Ernst Dating: 14.02.1918
BRIEF [O.A.] Thoden van Velzen, S... K... Author: Thoden van Velzen, S... K... Recipient: Haeckel, Ernst Dating: 17.02.1918
BRIEF [O.A.] Thoden van Velzen, Syo K... Author: Thoden van Velzen, Syo K... Recipient: Haeckel, Ernst Dating: 28.03.1918
BRIEF [O.A.] Thoden van Velzen, S... K... Author: Thoden van Velzen, S... K... Recipient: Haeckel, Ernst Dating: 04.06.1918