Cita APA (7th ed.)
(2000). Selling Skills for Professionals. Thorogood Publishing Ltd.
Cita Chicago (17th ed.)
Selling Skills for Professionals. Thorogood Publishing Ltd, 2000.
Cita MLA (9th ed.)
Selling Skills for Professionals. Thorogood Publishing Ltd, 2000.
Atenció: Aquestes cites poden no estar 100% correctes.