Hagel, J. I. (2002). Out of the box. Harvard Business School Publishing.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHagel, John III. Out of the Box. Boston: Harvard Business School Publishing, 2002.
एमएलए (9वां संस्करण) प्रशस्ति पत्रHagel, John III. Out of the Box. Harvard Business School Publishing, 2002.
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