Cita APA (7a ed.)

Drucker, P. F. (1999). Management challenges for the 21st century. Butterworth-Heinemann.

Cita Chicago Style (17a ed.)

Drucker, Peter F. Management Challenges for the 21st Century. Oxford: Butterworth-Heinemann, 1999.

Cita MLA (8a ed.)

Drucker, Peter F. Management Challenges for the 21st Century. Butterworth-Heinemann, 1999.