Manning, G., & Curtis, K. (1988). Leadership: Nine keys to success. Vista Systems.
Cita Chicago (17th ed.)Manning, George, i Kent Curtis. Leadership: Nine Keys to Success. Cincinnati, Ohio: Vista Systems, 1988.
Cita MLA (8th ed.)Manning, George, i Kent Curtis. Leadership: Nine Keys to Success. Vista Systems, 1988.
Atenció: Aquestes cites poden no estar 100% correctes.