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.
A primary source is an original object or document-- the raw material or first-hand information, source material that is closest to what is being studied. Primary sources vary by discipline and can include historical and legal documents, eye witness accounts, results of an experiment, statistical data, pieces of creative writing, and art objects.