Cita APA (7th ed.)
Koontz, H., & Weihrich, H. (1990). Essentials of management (4th. ed.). McGraw Hill.
Cita Chicago (17th ed.)
Koontz, Harold, i Heinz Weihrich. Essentials of Management. 4th. ed. New York: McGraw Hill, 1990.
Cita MLA (9th ed.)
Koontz, Harold, i Heinz Weihrich. Essentials of Management. 4th. ed. McGraw Hill, 1990.
Atenció: Aquestes cites poden no estar 100% correctes.