Cita APA (7th ed.)

Drucker, P. F. (2001). The Essential Drucker. Butterworth- Heinemann.

Cita Chicago (17th ed.)

Drucker, Peter F. The Essential Drucker. New Delhi: Butterworth- Heinemann, 2001.

Cita MLA (9th ed.)

Drucker, Peter F. The Essential Drucker. Butterworth- Heinemann, 2001.