WIA FC/1921/3/3 | 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 FC/1923/2/1 | Derenberg, Louise to Warburg, Aby 02/04/1923 | thanks him for birthday wishes to her husband Julius and herself; tells him of a performance in... |
WIA FC/1926/2/1 | 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 FC/1928/3/1 | Derenberg, Louise to Warburg, Aby 06/08/1928 | Mrs. Cassirer informed her that her husband will stay in Hamburg; congratulates Warburg on this... |