Barrera, R. (2005). Overpromise and overdeliver: The secrets of unshakable customer loyality. Penguin.
استشهاد بنمط شيكاغوBarrera, Rick. Overpromise and Overdeliver: The Secrets of Unshakable Customer Loyality. New Delhi: Penguin, 2005.
MLA استشهادBarrera, Rick. Overpromise and Overdeliver: The Secrets of Unshakable Customer Loyality. Penguin, 2005.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.