WIA GC/1910/411
Warburg, Aby to Marr, Heinz 22/11/1910
supplies names of people Marr ought to invite as well; [Heinrich?] Embden is prepared to bring...
WIA GC/1914/588
Warburg, Aby to Melchior, Carl 14/01/1914
he is very grateful to Melchior for his work for von [Wilhelm von] Beckerath; the businessman...
WIA GC/1914/589
Melchior, Carl to Warburg, Aby 15/01/1914
on the [Wilhelm von] Beckerath foundation; Alfred O'Swald has not paid yet; Warburg's brother...