The Treaty of Versailles in the mind of the Germans stabbed them in the back, especially the guilt clause that made them take blame for the First World War. Hitler capaitalized on these sentiments and used them to rally the German people.
Secondary Sources are materials that digest, analyze, evaluate and interpret information contained within primary sources or other secondary sources. Examples. 1  Autobiographies, memoirs, diaries, emails, oral histories.  Letters, correspondences, eyewitnesses.
Even though secondary sources are often acceptable, primary sources are often better than secondary sources, and there are times when primary sources must be used. While most of the sources that are found during research are secondary sources, it is often possible to also track down the primary source. To do this, look at the references, works cited, bibliography, or internet links (for an internet source) provided in a secondary source.