WIA GC/13250 | Derenberg, Julius to Warburg, Aby 20/03/1921 | congratulates him on the final exams of Marietta and Frede; his own son Carl and his nephew... |
WIA GC/17376 | Derenberg, Louise; Derenberg, Julius; Derenberg, Walter and Derenberg, Carl Julius to Warburg... | Louise sends birthday greetings; is sure that the new library building and events like Cassirer's... |
WIA GC/20023 | Derenberg, Louise to Warburg, Aby 06/08/1928 | Mrs. Cassirer informed her that her husband will stay in Hamburg; congratulates Warburg on this... |
WIA GC/22434 | Warburg, Max to Warburg, Aby 26/10/1928 | counters Warburg's complaints that his brothers do not reply to his letters; calls them... |
WIA GC/23390 | Warburg, Mary to Warburg, Aby 20/11/1902 | thanks him for letter; is pleased that he can work so well and that he has friends in Florence... |