Brian Tracy (2004). “Focal Point: A Proven System to Simplify Your Life, Double Your Productivity, and Achieve All Your Goals”, p.64, AMACOM Div American Mgmt Assn
Brian Tracy (2004). “Focal Point: A Proven System to Simplify Your Life, Double Your Productivity, and Achieve All Your Goals”, p.63, AMACOM Div American Mgmt Assn
Brian Tracy (1996). “Advanced Selling Strategies: The Proven System of Sales Ideas, Methods, and Techniques Used by Top Salespeople”, p.165, Simon and Schuster