Covey, S. R. (1991). Principle-centered leadershipages (First edition.). A Fireside Book.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCovey, Stephen R. Principle-centered Leadershipages. First edition. New York: A Fireside Book, 1991.
एमएलए (9वां संस्करण) प्रशस्ति पत्रCovey, Stephen R. Principle-centered Leadershipages. First edition. A Fireside Book, 1991.
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