BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Altmann-Bronn, Ida Dating: 26.05.1911
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Altmann-Bronn, Ida Dating: 26.02.1913
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Altmann-Bronn, Ida Dating: 24.08.1918