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.
Other types of primary sources are paintings created by the artist. If it were a photocopy of the painting, then it would be a secondary source. Some other primary sources are letters, films, short stories, plays, poems, photographs, court cases, journal articles, newspaper events, and speeches. For instance, a speech by President Bush would be a primary source.