Bis zur letzten Stunde by Traudl Junge (Hitler’s secretary) and Der Untergang from www.amazon.de in the original German (must make an effort to improve it, you see…)
When I’ve slogged my way through one of them with the aid of a dictionary, I’ll tell you how it was. Traudl Junge is one of the focus characters in the film Der Untergang, so her story should be particularly interesting.