Cita APA (7th ed.)

Drucker, P. F. (2001). Management Challenges for the 21st Century. HarperCollins Publishers.

Cita Chicago (17th ed.)

Drucker, Peter F. Management Challenges for the 21st Century. New York: HarperCollins Publishers, 2001.

Cita MLA (9th ed.)

Drucker, Peter F. Management Challenges for the 21st Century. HarperCollins Publishers, 2001.