Drucker, P. F. (2001). Management Challenges for the 21st Century. HarperCollins Publishers.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रDrucker, Peter F. Management Challenges for the 21st Century. New York: HarperCollins Publishers, 2001.
एमएलए (9वां संस्करण) प्रशस्ति पत्रDrucker, Peter F. Management Challenges for the 21st Century. HarperCollins Publishers, 2001.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.