WIA GC/1908/60 | Brandis, Otto to Warburg, Aby 12/03/1908 | apologizes for his late reply to Warburg's letter inviting him to join the new German Society... |
WIA GC/1908/61 | Warburg, Aby to Brandis, Otto 13/03/1908 | thanks him for his interest in the 'Deutscher Verein für Kunstwissenschaft'; hopes that he will join |
WIA GC/1913/187 | Brandis, Otto to Warburg, Aby [1913] | thanks him for photographs and the time he spent in his library |
WIA GC/1917/103 | Brandis, Otto to Warburg, Aby 09/07/1917 | he is in hospital and would like to read books on Vittorio Pisano Baldovinetti, Piero della... |
WIA GC/1925/931 | Melle, Werner von to Warburg, Aby 10/01/1925 | supplies reference for a Wilhelm von Humboldt quote; mentions Otto Brandis, Ferdinand von... |