GUPTA SUNIL. (2009). PERSUASIVE SELLING SKILLS. IDEAS MANAGEMENT CONSULTANTS.
Citazione stile Chigago Style (17a edizione)GUPTA SUNIL. PERSUASIVE SELLING SKILLS. INDIA: IDEAS MANAGEMENT CONSULTANTS, 2009.
Citatione MLA (9a ed.)GUPTA SUNIL. PERSUASIVE SELLING SKILLS. IDEAS MANAGEMENT CONSULTANTS, 2009.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.