BRIEF [O.A.] Hanitsch, Richard Author: Hanitsch, Richard Recipient: Haeckel, Ernst Dating: 21.01.1904
BRIEF [O.A.] Hanitsch, Richard Author: Hanitsch, Richard Recipient: Haeckel, Ernst Corporation: Raffles Museum Dating: 05.12.1904
TELEGRAMM Rautenfeld, Paul von Author: Rautenfeld, Paul von Recipient: Haeckel, Ernst Dating: 16.02.1904