BRIEF OHNE UMSCHLAG Haeckel, Karl; Haeckel, Hermine Author: Haeckel, Karl; Haeckel, Hermine Recipient: Haeckel, Ernst Dating: 06.05.1857
BRIEF OHNE UMSCHLAG Sethe, Hermine Author: Sethe, Hermine Recipient: Haeckel, Ernst Dating: 14.02.1858
BRIEF OHNE UMSCHLAG Sethe, Anna; Haeckel, Karl Author: Sethe, Anna; Haeckel, Karl Recipient: Haeckel, Ernst Dating: 21.05.1859