Drucker, P. F. (1999). Management challenges for the 21st century (First edition.). HarperBusiness.
Chicago (17e ed.) BronvermeldingDrucker, Peter F. Management Challenges for the 21st Century. First edition. New York: HarperBusiness, 1999.
MLA (8e ed.) BronvermeldingDrucker, Peter F. Management Challenges for the 21st Century. First edition. HarperBusiness, 1999.
Let op: Deze citaties zijn niet altijd 100% accuraat.