Sewell Carl. (1990). Customers for Life: How to turn that one-time buyer into a lifetime customer. Pocket Books Publishing.
Citazione stile Chigago Style (17a edizione)Sewell Carl. Customers for Life: How to Turn That One-time Buyer into a Lifetime Customer. NewYok: Pocket Books Publishing, 1990.
Citatione MLA (9a ed.)Sewell Carl. Customers for Life: How to Turn That One-time Buyer into a Lifetime Customer. Pocket Books Publishing, 1990.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.