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.
Primary sources are the first hand evidence left behind by participants or observers at the time of events. Primary sources originate in the time period that historians are studying. They vary a great deal.
Primary sources and secondary sources. Primary sources are first hand sources. For instance, an inscription on a wall, a painting, interviews, diaries and the like. Whereas, a secondary source is when you obtain information from someone or something else. For instance, a newspaper or a magazine.