Reichheld, F. F. (2006). The ultimate question: Driving good profits and true growth (NA.). Harvard Business School Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रReichheld, Frederick F. The Ultimate Question: Driving Good Profits and True Growth. NA. USA: Harvard Business School Press, 2006.
एमएलए (9वां संस्करण) प्रशस्ति पत्रReichheld, Frederick F. The Ultimate Question: Driving Good Profits and True Growth. NA. Harvard Business School Press, 2006.
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