BRIEF [O.A.] Gonzenbach, Magdalena von Author: Gonzenbach, Magdalena von Recipient: Haeckel, Ernst Dating: 01.03.1899
BRIEF [O.A.] Gonzenbach, Magdalena von Author: Gonzenbach, Magdalena von Recipient: Haeckel, Ernst Dating: 12.03.1899
POSTKARTE Gonzenbach, Magdalena von Author: Gonzenbach, Magdalena von Recipient: Haeckel, Ernst Dating: 13.02.1904
BRIEF [O.A.] Giannini, P... de Donato Author: Giannini, P... de Donato Recipient: Haeckel, Ernst Corporation: R. Istituto Tecnico e Nautico Dating: 26.02.1895
BRIEF OHNE UMSCHLAG Hertwig, Oscar; Hertwig, Richard Author: Hertwig, Oscar; Hertwig, Richard Recipient: Haeckel, Ernst Dating: 16.01.1877
BRIEF OHNE UMSCHLAG Hertwig, Richard Author: Hertwig, Richard Recipient: Haeckel, Ernst Dating: 19.11.1876
BRIEF OHNE UMSCHLAG Hertwig, Richard Author: Hertwig, Richard Recipient: Haeckel, Ernst Dating: 07.01.1877
BRIEF OHNE UMSCHLAG Hertwig, Richard Author: Hertwig, Richard Recipient: Haeckel, Ernst Dating: 18.02.1877
BRIEF OHNE UMSCHLAG Hertwig, Richard Author: Hertwig, Richard Recipient: Haeckel, Ernst Dating: 11.03.1879