(Pearson Education) A candid look at the insight track of how an XP project works, representing all-access uncensored XP. Example is valued over explanation, using sample code and test examples to support the text. Offers insight into the trial and error, ebb and flow of a real XP project. Softcover.
At the time it was written, it surely was one of the high-recommendations. And still, nowadays it's worth to read it for any "Junior" and even PMs to see how they did the project.
If you wish a more academic insight in XP, it would be better to read Kent Beck's book.