Gaya APA

Reichheld, F, F, -. (2011). The Ultimate Question 2.0: How Net Promoter Companies Thrive in a Customer-Driven World (10). America: Harvard Business Review Press.

Gaya MLA

Reichheld, Frederick, F, -A. "The Ultimate Question 2.0: How Net Promoter Companies Thrive in a Customer-Driven World". 10 America: Harvard Business Review Press, 2011. Text.