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, Paul; Sarasin, Fritz Author: Sarasin, Paul; Sarasin, Fritz Recipient: Haeckel, Ernst Dating: 20.11.1905
BRIEF OHNE UMSCHLAG Sarasin, Fritz Author: Sarasin, Fritz Recipient: Haeckel, Ernst Dating: 14.09.1908