Gretz, K. F. (1996). Professional selling: A consultative approach. Irwin.
Chicagoスタイル(17版)引用形式Gretz, Karl F. Professional Selling: A Consultative Approach. Chicago: Irwin, 1996.
MLA(9版)引用形式Gretz, Karl F. Professional Selling: A Consultative Approach. Irwin, 1996.
警告: この引用は必ずしも正確ではありません.