Dyfyniad APA

Covey, S. R. (1991). Principle-Centred Leadership. Pocket Books.

Dyfyniad Arddull Chicago

Covey, Stephen R. Principle-Centred Leadership. London: Pocket Books, 1991.

Dyfyniad MLA

Covey, Stephen R. Principle-Centred Leadership. Pocket Books, 1991.

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