APA-viite (7. p.)

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

Chicago-viite (17. p.)

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

MLA-viite (8. p.)

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