Cita APA (7a ed.)

Walther, G. R. (1994). Upside-down marketing: Turning your ex-customers into your best customers. McGraw-Hill.

Cita Chicago Style (17a ed.)

Walther, George R. Upside-down Marketing: Turning Your Ex-customers into Your Best Customers. Madrid: McGraw-Hill, 1994.

Cita MLA (8a ed.)

Walther, George R. Upside-down Marketing: Turning Your Ex-customers into Your Best Customers. McGraw-Hill, 1994.