Bringing Out the Best In Yourself at Work: How to Use the Enneagram System for Success by Ginger Lapid-Bogda Ph.D. (McGraw-Hill, 2004)
Now, Discover Your Strengths by Marcus Buckingham and Donald O. Clifton. (Free Press, 2001)
Getting Things Done: The Art of Stress-Free Productivity by David Allen. (Penguin, 2002)
The 7 Habits of Highly Effective People by Stephen R. Covey (Simon & Schuster, 1991)
The Making of a Corporate Athlete by Jim Loehr and Tony Schwartz. Harvard Business Review Reprint #R0101H