BRIEF OHNE UMSCHLAG Kükenthal, Willy Author: Kükenthal, Willy Recipient: Haeckel, Ernst Dating: 08.08.1894
BRIEF OHNE UMSCHLAG Kükenthal, Willy Author: Kükenthal, Willy Recipient: Haeckel, Ernst Dating: 25.10.1894
BRIEF OHNE UMSCHLAG Kükenthal, Willy Author: Kükenthal, Willy Recipient: Haeckel, Ernst Dating: 16.02.1894
BRIEF OHNE UMSCHLAG Kükenthal, Willy Author: Kükenthal, Willy Recipient: Haeckel, Ernst Dating: 11.07.1894