WIA GC/1899/56 | Müller, August Wilhelm Friedrich to Warburg, Aby 08/05/1899 | the Kunsthalle has photographs of Leonardo paintings from the publication by [Charles] Ravaisson... |
WIA GC/1903/206 | Warburg, Aby to Müller, August Wilhelm Friedrich 21/07/1903 | requests the address of Professor A. Lichtwark |
WIA GC/1903/207 | Müller, August Wilhelm Friedrich to Warburg, Aby 23/07/1903 | on the purchase of the missing volumes of 'Repertorium für Kunstwissenschaft'; the Kunsthalle is... |
WIA GC/1903/256 | Schwedeler-Meyer, Ernst to Warburg, Aby 17/08/1903 | on personnel movements in the National-Galerie; mentions [A.W. F.] Müller, who is too 'modern... |
WIA GC/1906/487 | Müller, August Wilhelm Friedrich to Warburg, Aby 25/04/1906 | request to return books to the Kunsthalle |