BRIEF [O.A.] Margittai, Richard Author: Margittai, Richard Recipient: Haeckel, Ernst Dating: 13.02.1917
BRIEF [O.A.] Margittai, Richard Author: Margittai, Richard Recipient: Haeckel, Ernst Dating: 13.02.1918
BRIEF [O.A.] Margittai, Richard Author: Margittai, Richard Recipient: Haeckel, Ernst Dating: 14.02.1916
BRIEF [O.A.] Margittai, Richard Author: Margittai, Richard Recipient: Haeckel, Ernst Dating: 12.02.1919
BRIEF [O.A.] Margittai, Richard Author: Margittai, Richard Recipient: Haeckel, Ernst Dating: 15.03.1914
BRIEF [O.A.] Margittai, Richard Author: Margittai, Richard Recipient: Haeckel, Ernst Dating: 16.02.1915
BRIEF [O.A.] Margittai, Richard Author: Margittai, Richard Recipient: Haeckel, Ernst Dating: 31.05.1915