WIA GC/1910/129 | 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/1910/130 | Warburg, Aby to Derenberg, Richard 14/12/1910 | thanks him for the Japanese reproduction; informs him of a project of the 'Verein Hamburgischer... |
WIA GC/1915/170 | Warburg, Aby to Derenberg, Richard 15/08/1915 | on the commemorative print ['Gedenkblatt'] for the centenary of the birthday of his grandmother... |
WIA GC/1915/171 | Derenberg, Richard to Warburg, Aby 30/08/1915 | thanks him for the corrections on the proofs; Warburg's mother will receive draft pages in... |