WIA GC/12248 | Warburg, Aby to Derenberg, Richard 15/08/1915 | on the commemorative print ['Gedenkblatt'] for the centenary of the birthday of his grandmother... |
WIA GC/12261 | Warburg, Aby to Derenberg, Richard 27/08/1915 | on the commemorative print 'Gedenkblatt an Frau Regine Oppenheim'; lists mistakes; requests... |
WIA GC/32095 | Warburg, Mary to Warburg, Aby 30/06/1909 | thanks him for cable; is sorry that Warburg could not get his old room in Bufe's house; will Bufe... |
WIA GC/3656 | Derenberg, Richard to Warburg, Aby 12/12/1910 | thanks him for his kind words about their Holbein pamphlet; encloses a reproduction of a Japanese... |
WIA GC/3657 | Warburg, Aby to Derenberg, Richard 14/12/1910 | thanks him for the Japanese reproduction; informs him of a project of the 'Verein Hamburgischer... |