BRIEF OHNE UMSCHLAG Daelen, Eduard Author: Daelen, Eduard Recipient: Haeckel, Ernst Dating: 06.03.1917
BRIEF OHNE UMSCHLAG Daelen, Eduard Author: Daelen, Eduard Recipient: Haeckel, Ernst Dating: 02.08.1917
BRIEF OHNE UMSCHLAG Daelen, Eduard Author: Daelen, Eduard Recipient: Haeckel, Ernst Dating: 14.08.1917