Sewell, C., & Brown, P. B. (2002). Customers for Life: How to Turn that One-time Buyer into a Lifetime Customer. Crown.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Sewell, Carl, و Paul B. Brown. Customers for Life: How to Turn That One-time Buyer into a Lifetime Customer. New York: Crown, 2002.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Sewell, Carl, و Paul B. Brown. Customers for Life: How to Turn That One-time Buyer into a Lifetime Customer. Crown, 2002.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.