BRIEF OHNE UMSCHLAG Quillet, Aristide Author: Quillet, Aristide Recipient: Haeckel, Ernst Dating: 26.12.1912
BRIEF OHNE UMSCHLAG Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 10.01.1912
BRIEF OHNE UMSCHLAG Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 10.01.1912
BRIEF [O.A.] Pappert, Fr... Jos... Author: Pappert, Fr... Jos... Recipient: Haeckel, Ernst Dating: 08.09.1912
POSTKARTE Grand-Carteret, I... Author: Grand-Carteret, I... Recipient: Haeckel, Ernst Dating: 01.03.1912
BRIEF OHNE UMSCHLAG Quillet, Aristide Author: Quillet, Aristide Recipient: Haeckel, Ernst Dating: 18.12.1912