English professor Don Foster's
unique view of the world — and literature — came to light when he
figured out that Joe Klein, who had been lying about his authorship,
really was the writer of Primary Colors.  In Author Unknown,
Foster lays out his personal history and interest in content analysis,
along with his methodology.  The result is a good read that can
show journalists how to use easily available tools to analyze text of
any sort.  Highly recommended, and plenty of used copies via the
online market.

“In Author Unknown, Don
Foster reveals a startling fact: since no two people use language in
precisely the same way, our
identities are encoded in our own language, a kind of literary DNA.
Combining
traditional scholarship with modern technology, Foster has discovered
how to unlock that code and, in the process, has invented an entire
field of
investigation — literary forensics — by which it becomes possible to
catch anonymous authors as they betray their identities with their own
words.”
Source: http://www.fsbassociates.com/holt/authorunknown.htm#order