The text from Lewicki, Barry, and Saunders is the most complete - and comprehensive - compilation of articles, cases, and exercises I've found in my teaching Negotiations at college, University, and corporate business.
The authors/editors have selected excellent articles from some of the foremost writers on Negotiation ... and coupled them with cases which highlight what you've just read. I have recommended it to friends, and continute to select it for graduate level courses in Negotiations. My students like the text, and plan to keep it on their shelves (rather than sell it back to the bookstore).