BRIEF OHNE UMSCHLAG Sarasin, Fritz Author: Sarasin, Fritz Recipient: Haeckel, Ernst Dating: 20.03.1900
BRIEF OHNE UMSCHLAG Sarasin, Fritz Author: Sarasin, Fritz Recipient: Haeckel, Ernst Dating: 09.11.1901
BRIEF OHNE UMSCHLAG Sarasin, Fritz Author: Sarasin, Fritz Recipient: Haeckel, Ernst Dating: 14.09.1908
BRIEF OHNE UMSCHLAG Sarasin, Fritz Author: Sarasin, Fritz Recipient: Haeckel, Ernst Dating: 29.10.1916