BRIEF OHNE UMSCHLAG Haeckel, Karl Author: Haeckel, Karl Recipient: Haeckel, Carl Gottlob; Haeckel, Charlotte Dating: 20.04.1866
BRIEF OHNE UMSCHLAG Haeckel, Karl Author: Haeckel, Karl Recipient: Haeckel, Ernst; Haeckel, Agnes Dating: 29.09.1868
BRIEF OHNE UMSCHLAG Haeckel, Karl Author: Haeckel, Karl Recipient: Haeckel, Carl Gottlob; Haeckel, Charlotte Dating: 21.02.1863
BRIEF OHNE UMSCHLAG Haeckel, Karl Author: Haeckel, Karl Recipient: Haeckel, Carl Gottlob; Haeckel, Charlotte Dating: 10.01.1863
BRIEF OHNE UMSCHLAG Haeckel, Karl Author: Haeckel, Karl Recipient: Haeckel, Charlotte Dating: 14.10.1868