BRIEF OHNE UMSCHLAG N.N. Author: N.N. Recipient: Haeckel, Ernst Corporation: Behn, Meyer & Co. Dating: 30.10.1900
BRIEF [O.A.] Hanitsch, Richard Author: Hanitsch, Richard Recipient: Haeckel, Ernst Corporation: Raffles Museum Dating: 26.05.1900
BRIEF [O.A.] Hanitsch, Richard Author: Hanitsch, Richard Recipient: Haeckel, Ernst Corporation: Raffles Museum Dating: 14.07.1900
BRIEF [O.A.] Hanitsch, Richard Author: Hanitsch, Richard Recipient: Haeckel, Ernst Corporation: Raffles Museum Dating: 19.10.1900
BRIEF [O.A.] Hanitsch, Richard Author: Hanitsch, Richard Recipient: Haeckel, Ernst Corporation: Raffles Museum Dating: 12.11.1900