BRIEF OHNE UMSCHLAG Kükenthal, Willy Author: Kükenthal, Willy Recipient: Haeckel, Ernst Dating: 14.02.1904
BRIEF OHNE UMSCHLAG Kükenthal, Willy Author: Kükenthal, Willy Recipient: Haeckel, Ernst Dating: 14.02.1904
POSTKARTE Morawetz-Dierkes, Leopoldine von Author: Morawetz-Dierkes, Leopoldine von Recipient: Haeckel, Ernst Dating: 06.03.1904
POSTKARTE Pulvermacher, Th... Author: Pulvermacher, Th... Recipient: Haeckel, Ernst Dating: 14.02.1904