BRIEF OHNE UMSCHLAG Engesser, Leonie Author: Engesser, Leonie Recipient: Haeckel, Ernst Dating: 04.08.1892
BRIEF OHNE UMSCHLAG Engesser, Leonie Author: Engesser, Leonie Recipient: Haeckel, Ernst Dating: 09.10.1892
BRIEF OHNE UMSCHLAG Engesser, Leonie Author: Engesser, Leonie Recipient: Haeckel, Ernst Dating: 29.11.1892