BRIEF OHNE UMSCHLAG Umrath, Wilhelm Author: Umrath, Wilhelm Recipient: Haeckel, Ernst Dating: 04.05.1911
BRIEF OHNE UMSCHLAG Umrath, Wilhelm Author: Umrath, Wilhelm Recipient: Haeckel, Ernst Dating: 05.07.1911
BRIEF OHNE UMSCHLAG Recipient: Haeckel, Ernst Corporation: Wiener Bank-Verein. Filiale Prag. Dating: 05.05.1911