Schiffman, S. (2012). The power of positive selling: 30 surefire techniques to win new clients, boost your commission, and build the mindset for success. McGraw-Hill.
Cita Chicago (17th ed.)Schiffman, Stephan. The Power of Positive Selling: 30 Surefire Techniques to Win New Clients, Boost Your Commission, and Build the Mindset for Success. New York: McGraw-Hill, 2012.
Cita MLA (9th ed.)Schiffman, Stephan. The Power of Positive Selling: 30 Surefire Techniques to Win New Clients, Boost Your Commission, and Build the Mindset for Success. McGraw-Hill, 2012.
Atenció: Aquestes cites poden no estar 100% correctes.