Dyfyniad APA

Drucker, P. F. (1999). Management challenges for the 21st century (First edition.). HarperBusiness.

Dyfyniad Arddull Chicago

Drucker, Peter F. Management Challenges for the 21st Century. First edition. New York: HarperBusiness, 1999.

Dyfyniad MLA

Drucker, Peter F. Management Challenges for the 21st Century. First edition. HarperBusiness, 1999.

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