BRIEF OHNE UMSCHLAG Magnussen, Harro Author: Magnussen, Harro Recipient: Haeckel, Ernst Dating: 12.02.1906
BRIEF OHNE UMSCHLAG Magnussen, Harro Author: Magnussen, Harro Recipient: Haeckel, Ernst Dating: 19.09.1906
BRIEF OHNE UMSCHLAG Magnussen, Harro Author: Magnussen, Harro Recipient: Haeckel, Ernst Dating: 09.12.1906