Four kinds of information a writer must document are: Direct quotations, summary of a discussion, common knowledge information and writer constructs a diagram from data provided by others. These kinds of information are essential for a writer to document.
This was an event in Vonnegut's own life, and the novel is
considered semi-autobiographical. from his time as an American soldier and
chaplain's assistant, to post war and early years. It is generally recognized
as Vonnegut's most influential and popular work.