APA-viite (7. p.)

Reichheld, F. F. (2006). The ultimate question: Driving good profits and true growth (NA.). Harvard Business School Press.

Chicago-viite (17. p.)

Reichheld, Frederick F. The Ultimate Question: Driving Good Profits and True Growth. NA. USA: Harvard Business School Press, 2006.

MLA-viite (9. p.)

Reichheld, Frederick F. The Ultimate Question: Driving Good Profits and True Growth. NA. Harvard Business School Press, 2006.