Hide a Dagger Behind a Smile: Use the 36 Ancient Chinese Strategies to Seize the Competitive Edge
http://www.amazon.com/Hide-Dagger-Behind-Smile-Competitive/d...
The Prince
http://www.amazon.com/Prince-Niccolo-Machiavelli/dp/03121497...
and
The Art of Worldly Wisdom
http://www.amazon.com/Art-Worldly-Wisdom-Balthasar-Gracian/d...
I got a lot out of reading Outthink the Competition and am planning to read it again soon. I like his ideas about "coordinating the uncoordinated" and "take what's left behind when the battle moves elsewhere" (paraphrasing in both cases).
[1]: http://www.amazon.com/Outthink-Competition-Generation-Strate...
[2]: http://www.amazon.com/Hide-Dagger-Behind-Smile-Competitive/d...