Denton, D. K. (1989). Quality service: How America's top companies are competing in the customer-service revolution - and how you can too. Gulf Pub.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Denton, D. Keith. Quality Service: How America's Top Companies Are Competing in the Customer-service Revolution - and How You Can Too. Houston, Tex: Gulf Pub, 1989.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Denton, D. Keith. Quality Service: How America's Top Companies Are Competing in the Customer-service Revolution - and How You Can Too. Gulf Pub, 1989.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.