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.
Primary sources are original materials that have not been altered or distorted in any way. In the study of history as an academic discipline, a primary source (also called original source or evidence) is an artifact, a document, a recording, or other source of information that was created at the time under study.