Reichheld, F. F. (2006). The ultimate question: Driving good profits and true growth (NA.). Harvard Business School Press.
Chicago-referens (17:e uppl.)Reichheld, Frederick F. The Ultimate Question: Driving Good Profits and True Growth. NA. USA: Harvard Business School Press, 2006.
MLA-referens (9:e uppl.)Reichheld, Frederick F. The Ultimate Question: Driving Good Profits and True Growth. NA. Harvard Business School Press, 2006.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.