Check the foot- or endnotes or look at the reference list. Knowing where the
author got the information and what sources were used will tell you whether the
author is looking at something new (interviews, letters, archival or government
documents, etc.), taking a new look at something old (books and articles), or combining
new and old and thus adding to the discussion of the subject. Looking at
the sources can show if the author has concentrated on a particular kind of information
or point of view.