BRIEF [O.A.] Schulte, Peter F... Author: Schulte, Peter F... Recipient: Haeckel, Ernst Dating: 24.02.1914
BRIEF [O.A.] Sars, Georg Ossian Author: Sars, Georg Ossian Recipient: Haeckel, Ernst Dating: 29.11.1869
BRIEF [O.A.] Sars, Georg Ossian Author: Sars, Georg Ossian Recipient: Haeckel, Ernst Dating: 17.01.1873
BRIEF [O.A.] Sars, Georg Ossian Author: Sars, Georg Ossian Recipient: Haeckel, Ernst Dating: 01.12.1891