BRIEF OHNE UMSCHLAG Hirschfeld, Magnus Author: Hirschfeld, Magnus Recipient: Haeckel, Ernst Dating: 05.02.1917
BRIEF OHNE UMSCHLAG Hirschfeld, Magnus Author: Hirschfeld, Magnus Recipient: Haeckel, Ernst Dating: 22.08.1917
BRIEF OHNE UMSCHLAG Hirschfeld, Magnus Author: Hirschfeld, Magnus Recipient: Haeckel, Ernst Dating: 30.08.1917