BRIEF [O.A.] Bischoff, Alfred Author: Bischoff, Alfred Recipient: Haeckel, Ernst Corporation: Alfred Bischoff, Künstlerische Photographie Dating: 01.10.1913
BRIEF [O.A.] Bischoff, Alfred Author: Bischoff, Alfred Recipient: Haeckel, Ernst Corporation: Alfred Bischoff, Künstlerische Photographie Dating: 06.01.1914
BRIEF [O.A.] Bischoff, Alfred Author: Bischoff, Alfred Recipient: Haeckel, Ernst Corporation: Alfred Bischoff, Photograph Dating: 16.02.1917
BRIEF [O.A.] Bischoff, Alfred Author: Bischoff, Alfred Recipient: Haeckel, Ernst Corporation: Alfred Bischoff, Photograph Dating: 16.02.1918