WIA GC/1900/88 | Steffen, Gustaf F., Steffen, Oscara and Ehrenberg, Richard to Warburg, Aby and Warburg, Mary 22... | New Year Greetings |
WIA GC/1902/423 | Steffen, Oscara to Warburg, Aby and Warburg, Mary 09/08/1902 | congratulations on the birth of the second child, Max Adolph; they moved from Florence to... |
WIA GC/1905/576 | Steffen, Gustaf F., Steffen, Oscara to Warburg, Aby and Warburg, Mary 21/12/1905 | Christmas and New Year greetings |
WIA GC/1913/1084 | Steffen, Gustaf F. and Steffen, Oscara to Warburg, Aby 09/03/1913 | thanks him for the 'Luftschiff' essay; news of their family |
WIA GC/1914/844 | Steffen, Gustaf F. to Warburg, Aby 26/06/1914 | he is the only candidate for the post in Berlin; now the ministry of commerce has to decide; he... |