Seelye,Richard S. (1993). The selling starts when the customer says no: The twelve toughest sells and how to overcome them. Probus Publishing Co.
Cita Chicago (17th ed.)Seelye,Richard S. The Selling Starts When the Customer Says No: The Twelve Toughest Sells and How to Overcome Them. Chicago: Probus Publishing Co, 1993.
Cita MLA (9th ed.)Seelye,Richard S. The Selling Starts When the Customer Says No: The Twelve Toughest Sells and How to Overcome Them. Probus Publishing Co, 1993.
Atenció: Aquestes cites poden no estar 100% correctes.